diff --git a/du3/program.c b/du3/program.c
index 83a0772..4a4ed42 100644
--- a/du3/program.c
+++ b/du3/program.c
@@ -1,93 +1,61 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <math.h>
 
-#define STACK_SIZE 10
+#define SIZE 10
 
-struct stack {
-    float values[STACK_SIZE];
-    int size;
-};
+int main(void) {
+    double ulozisko[SIZE];
+    int top = 0;
+    char vstup[64];
 
-int is_operator(const char *str) {
-    return (strcmp(str, "+") == 0 ||
-            strcmp(str, "-") == 0 ||
-            strcmp(str, "*") == 0 ||
-            strcmp(str, "/") == 0);
-}
+    while (fgets(vstup, sizeof(vstup), stdin)) {
+        vstup[strcspn(vstup, "\n")] = 0;
 
-void push_stack(struct stack *s, float value) {
-    if (s->size >= STACK_SIZE) {
-        printf("Chyba: zásobník je plný.\n");
-        exit(1);
-    }
-    s->values[s->size++] = value;
-}
-
-void p_stack(struct stack *s) {
-    for (int i = 0; i < s->size; i++) {
-        (fabsf(s->values[i] - (int)s->values[i]) < 1e-6) ? 
-            printf("%d", (int)s->values[i]) : printf("%g", s->values[i]);
-        if (i < s->size - 1) printf(" ");
-    }
-    printf("\n");
-}
-
-float remove_stack(struct stack *s) {
-    if (s->size <= 0) {
-        printf("Chyba: prázdny zásobník.\n");
-        exit(1);
-    }
-    return s->values[--s->size];
-}
-
-int main() {
-    struct stack mystack = { .size = 0 };
-    char input[100];
-
-    while (1) {
-        printf("> ");
-        fflush(stdout);
-
-        if (!fgets(input, sizeof(input), stdin)) break;
-
-        input[strcspn(input, "\n")] = 0; 
-
-        if (!*input) {
-            printf("no input \n");
-            break;
+        if (strlen(vstup) == 0) {
+            printf("no input\n");
+            return 0;
         }
 
-        char *endptr;
-        float value = strtof(input, &endptr);
+        char *koniec;
+        double cislo = strtod(vstup, &koniec);
 
-        if (endptr != input && *endptr == '\0') {
-            push_stack(&mystack, value);
-            p_stack(&mystack);
-        } else if (is_operator(input)) {
-            if (mystack.size < 2) {
-                printf("Chyba: nedostatok hodnôt v zásobníku.\n");
-                exit(1);
+        if (*koniec == '\0') {
+            if (top >= SIZE) {
+                printf("stack full\n");
+                return 0;
+            }
+            ulozisko[top++] = cislo;
+        } 
+        else if (strlen(vstup) == 1 && strchr("+-*/", vstup[0])) {
+            if (top < 2) {
+                printf("not enough values\n");
+                return 0;
+            }
+            double b = ulozisko[--top];
+            double a = ulozisko[--top];
+            double vysledok = 0.0;
+
+            switch (vstup[0]) {
+                case '+': vysledok = a + b; break;
+                case '-': vysledok = a - b; break;
+                case '*': vysledok = a * b; break;
+                case '/': vysledok = b == 0 ? (printf("divide by zero\n"), exit(0), 0) : a / b; break;
+                default: printf("invalid op\n"); return 0;
             }
 
-            float b = remove_stack(&mystack);
-            float a = remove_stack(&mystack);
-
-            float res = strcmp(input, "+") == 0 ? a + b :
-                        strcmp(input, "-") == 0 ? a - b :
-                        strcmp(input, "*") == 0 ? a * b :
-                        strcmp(input, "/") == 0 ? 
-                            (b == 0 ? (printf("Chyba: delenie nulou.\n"), exit(1), 0) : a / b)
-                        : 0;
-
-            push_stack(&mystack, res);
-            p_stack(&mystack);
-        } else {
-            printf("Chyba: neplatný vstup.\n");
-            exit(1);
+            ulozisko[top++] = vysledok;
+        } 
+        else {
+            printf("invalid input\n");
+            return 0;
         }
+
+        for (int i = 0; i < top; i++)
+            printf("%.2f ", ulozisko[i]);
+        printf("\n");
     }
 
+    printf("no input\n");
     return 0;
 }