diff --git a/Makefile b/Makefile
index 8e61469..060358d 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 CC = gcc
 CFLAGS = -Wall -Wextra -std=c99
-dIRS = a1 du1 du2 du3 du4 du5
+dIRS = a1 du1 du2 du3 du4 du5 a3
 all: 
 	@for %%d in ($(dIRS)) do \
 		$(CC) $(CFLAGS) %%d\program.c -o %%d\program.exe
diff --git a/a3/Makefile b/a3/Makefile
new file mode 100644
index 0000000..f15718e
--- /dev/null
+++ b/a3/Makefile
@@ -0,0 +1,19 @@
+CC = gcc
+CFLAGS = -Wall -Wextra -std=c99
+
+OBJS = main.o snake.o world.o
+
+snake: $(OBJS)
+	$(CC) $(CFLAGS) -o snake $(OBJS)
+
+main.o: main.c snake.h world.h
+	$(CC) $(CFLAGS) -c main.c
+
+snake.o: snake.c snake.h
+	$(CC) $(CFLAGS) -c snake.c
+
+world.o: world.c world.h snake.h
+	$(CC) $(CFLAGS) -c world.c
+
+clean:
+	del *.o *.exe
\ No newline at end of file
diff --git a/a3/main.c b/a3/main.c
new file mode 100644
index 0000000..7ee1a4d
--- /dev/null
+++ b/a3/main.c
@@ -0,0 +1,42 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <unistd.h>
+#endif
+
+#include "snake.h"
+#include "world.h"
+
+int main(void) {
+    struct state game_state;
+
+    setup_world(&game_state, 20, 10);
+    draw_world(&game_state);
+
+    while (1) {
+        char command = read_input();
+
+        change_direction(&game_state, command);
+
+        int outcome = step_state(&game_state);
+        draw_world(&game_state);
+
+        if (outcome != END_CONTINUE) {
+            break;
+        }
+
+#ifdef _WIN32
+        Sleep(1000);  
+#else
+        sleep(1);    
+#endif
+    }
+
+    free_snake(game_state.snake);
+    printf("\n--- KONIEC HRY ---\n");
+
+    return 0;
+}
diff --git a/a3/main.o b/a3/main.o
new file mode 100644
index 0000000..79356d2
Binary files /dev/null and b/a3/main.o differ
diff --git a/a3/snake.c b/a3/snake.c
new file mode 100644
index 0000000..8ab3ecb
--- /dev/null
+++ b/a3/snake.c
@@ -0,0 +1,110 @@
+#include <stdio.h>
+#include "snake.h"
+#include <stdlib.h>
+
+struct snake* add_snake (struct snake* snake, int x, int y) {
+    struct snake* head = NULL;
+
+    head = malloc(sizeof(struct snake));
+
+    if (!head) {
+        return snake;
+    }    
+        head->x = x;
+        head->y = y;
+
+        head->next = NULL;
+
+        if (snake !=NULL) {
+            head->next = snake;
+        }
+        return head;
+}
+
+struct snake* remove_snake(struct snake* snake) {
+    if (snake == NULL) {
+        return NULL;
+    }
+
+    if (snake->next == NULL) {
+        free(snake);
+        return NULL;
+    }
+
+    struct snake* temp = snake;
+    while (temp->next->next != NULL) {
+        temp = temp->next;
+    }
+
+    free(temp->next);
+    temp->next = NULL;
+
+    return snake;
+}
+
+void free_snake(struct snake* sn) {
+    struct snake* walker = sn;
+    struct snake* next_part = NULL;
+    while (walker !=NULL) {
+        next_part = walker->next;
+        free(walker);
+        walker = next_part;
+    }
+}
+
+int is_snake(struct snake* snake, int x, int y) {
+    struct snake* current = snake;
+
+    while (current !=NULL) {
+        if ((current->x==x) && (current->y==y)) {
+            return 1;
+        }
+        current = current->next;
+    }
+    return 0;
+}
+
+int step_state(struct state* state) {
+    int x = state->snake->x + state->sx;
+    int y = state->snake->y + state->sy;
+
+    if (x < 0) return END_WALL;
+    if (x >= state->width) return END_WALL;
+    if (y < 0) return END_WALL;
+    if (y >= state->height) return END_WALL;
+
+    if (is_snake(state->snake, x, y)) {
+        return END_SNAKE;
+    }
+
+    int food_found = -1;
+    for (int idx = 0; idx < FOOD_COUNT; idx++) {
+        if (state->foodx[idx] == x && state->foody[idx] == y) {
+            food_found = idx;
+            break;
+        }
+    }
+
+    if (food_found != -1) {
+        state->foodx[food_found] = -1;
+        state->foody[food_found] = -1;
+        state->snake = add_snake(state->snake, x, y);
+
+        int remaining = 0;
+        for (int k = 0; k < FOOD_COUNT; ++k) {
+            remaining += (state->foodx[k] >= 0 && state->foody[k] >= 0);
+        }
+
+        if (remaining == 0) {
+            return END_FOOD;
+        }
+        return END_CONTINUE;
+    }
+
+    state->snake = add_snake(state->snake, x, y);
+    state->snake = remove_snake(state->snake);
+
+    return END_CONTINUE;
+}
+
+
diff --git a/a3/snake.exe b/a3/snake.exe
new file mode 100644
index 0000000..594e170
Binary files /dev/null and b/a3/snake.exe differ
diff --git a/a3/snake.h b/a3/snake.h
new file mode 100644
index 0000000..df3a11b
--- /dev/null
+++ b/a3/snake.h
@@ -0,0 +1,111 @@
+#ifndef snake_h_INCLUDED
+#define snake_h_INCLUDED
+
+// Number of food items on the plane
+#define FOOD_COUNT 5
+
+/**
+ * One part of the snake;
+ * 
+ * The snake is a linked list;
+ */
+struct snake {
+    // x position of the snake part
+    int x;
+    // y position of the snake part
+    int y;
+    // Pointer to the next snake part.
+    // The last part of the snake has NULL pointer to the next part.
+    struct snake* next;
+};
+
+// End game reason constants, return value of step_state
+enum endgame {
+    // Continue the game
+    END_CONTINUE = 0,
+    // Snake hit a wall
+    END_WALL,
+    // Snake hit itself
+    END_SNAKE,
+    // No food left
+    END_FOOD,
+    // Other reason to end
+    END_USER
+};
+
+/**
+ * State of the game.
+ * 
+ * The state consists of the snake, its speed and food on the plane.
+ * 
+ * The snake is a linked list of snake parts.
+ * 
+ * Speed vector is a vector added to the last head position to create a new head.
+ * 
+ * Food are points on the plane. Food with negative coordinates means food is already eaten.
+ */
+struct state {
+    // Snake as a linked list
+    struct snake* snake;
+    // X of the food positions
+    int foodx[FOOD_COUNT];
+    // Y of the food positions
+    int foody[FOOD_COUNT];
+    int sx;
+    int sy;
+    int width;
+    int height;
+};
+
+/**
+ * Add a new snake part with given position. The new snake part becomes the new head.
+ *
+ * @param head of the snake.
+ * @param x coordinate of the new head;
+ * @param y coordinate of the new head.
+ * @return new head of the snake.
+ */
+struct snake* add_snake(struct snake* snake, int x, int y);
+
+/**
+ * Remove the last snake part.
+ * The last snake part  should always have NULL next pointer.
+ *
+ * @param head of the snake.
+ * @return new head of the snake.
+ */
+struct snake* remove_snake(struct snake* snake);
+
+/**
+ * Finds out if given coordinates are part of the snake.
+ * @param snake
+ * @param x coordinate to search in snake
+ * @param y coordinate to search in snake
+ * @return True, if there is a snake part with coordinates x,y. False otherwise
+ */
+int is_snake(struct snake* snake, int x, int y);
+
+/**
+ * Remove and free each snake part;
+ * @param head of the snake.
+ */
+void free_snake(struct snake* sn);
+
+/**
+ * Change game state.
+ *
+ * The function should calculate new position of the snake head
+ * from the current position and speed vector.
+ * Then it should modify snake parts or food coordinates according to the rules:
+ * 
+ * - If the new position is on the snake, end the game, return END_SNAKE.
+ * - If the new position is on the food, mark food as eaten
+ *   (set its coordinates to -1) and add new snake part on the position of the food. If there is no food left, return END_FOOD. Else return END_CONTINUE.
+ * - If the new position is on the plane, add new snake part on the new position and remove the last part of the snake, return END_CONTINUE.
+ * 
+ * @param current state of the game
+ * @return reason to end the game according to enum endgame.
+ */
+int step_state(struct state* state);
+
+#endif // snake_h_INCLUDED
\ No newline at end of file
diff --git a/a3/snake.o b/a3/snake.o
new file mode 100644
index 0000000..b4ddfcc
Binary files /dev/null and b/a3/snake.o differ
diff --git a/a3/world.c b/a3/world.c
new file mode 100644
index 0000000..38fe0d8
--- /dev/null
+++ b/a3/world.c
@@ -0,0 +1,109 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include "world.h"
+#include "snake.h"
+
+static void place_food(struct state* s) {
+    int placed = 0;
+
+    while (placed < FOOD_COUNT) {
+        int fx = rand() % s->width;
+        int fy = rand() % s->height;
+
+        if (!is_snake(s->snake, fx, fy)) {
+            s->foodx[placed] = fx;
+            s->foody[placed] = fy;
+            placed++;
+        }
+    }
+}
+
+void setup_world(struct state* s, int w, int h) {
+    if (!s) return;
+
+    srand((unsigned int)time(NULL));
+    s->width = w;
+    s->height = h;
+
+    s->sx = 1;
+    s->sy = 0;
+
+    s->snake = NULL;
+    int start_x = w / 2;
+    int start_y = h / 2;
+
+    s->snake = add_snake(s->snake, start_x, start_y);
+
+    place_food(s);
+}
+
+void draw_world(const struct state* s) {
+    if (!s) return;
+
+    system("clear"); // или "cls" на Windows
+
+    for (int row = 0; row < s->height; row++) {
+        for (int col = 0; col < s->width; col++) {
+            int drawn = 0;
+
+            if (is_snake(s->snake, col, row)) {
+                putchar('O');
+                drawn = 1;
+            } else {
+                for (int i = 0; i < FOOD_COUNT; ++i) {
+                    if (s->foodx[i] == col && s->foody[i] == row) {
+                        putchar('*');
+                        drawn = 1;
+                        break;
+                    }
+                }
+            }
+
+            if (!drawn) {
+                putchar('.');
+            }
+        }
+        putchar('\n');
+    }
+}
+
+char read_input(void) {
+    char key = 0;
+
+    printf("Zadaj smer (WASD): ");
+    scanf(" %c", &key);
+
+    return key;
+}
+
+void change_direction(struct state* s, char key) {
+    if (!s) return;
+
+    switch (key) {
+        case 'w':
+        case 'W':
+            s->sx = 0;
+            s->sy = -1;
+            break;
+        case 's':
+        case 'S':
+            s->sx = 0;
+            s->sy = 1;
+            break;
+        case 'a':
+        case 'A':
+            s->sx = -1;
+            s->sy = 0;
+            break;
+        case 'd':
+        case 'D':
+            s->sx = 1;
+            s->sy = 0;
+            break;
+        default:
+            // ничего не делаем при некорректном вводе
+            break;
+    }
+}
diff --git a/a3/world.h b/a3/world.h
new file mode 100644
index 0000000..3dbfc40
--- /dev/null
+++ b/a3/world.h
@@ -0,0 +1,11 @@
+#ifndef WORLD_MODULE_H
+#define WORLD_MODULE_H
+
+#include "snake.h"
+
+void setup_world(struct state* s, int w, int h);
+void draw_world(const struct state* s);
+char read_input(void);
+void change_direction(struct state* s, char key);
+
+#endif
diff --git a/a3/world.o b/a3/world.o
new file mode 100644
index 0000000..e539001
Binary files /dev/null and b/a3/world.o differ