diff --git a/cv3/program.c b/cv3/program.c
index 40e58c0..88a101b 100644
--- a/cv3/program.c
+++ b/cv3/program.c
@@ -1,56 +1,58 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <assert.h>
+#include <ctype.h>
 
 #define STACK_SIZE 10
 
-// Stack structure
 struct stack {
     float values[STACK_SIZE];
     int size;
 };
 
-// Function to print the stack
 void print_stack(struct stack* s) {
     for (int i = 0; i < s->size; i++) {
         printf("%.2f", s->values[i]);
         if (i < s->size - 1) {
-            printf(" ");  // Print space between values
+            printf(" ");
+        } else {
+            printf(" ");
         }
     }
     printf("\n");
 }
 
-// Function to push a value onto the stack
 void push_stack(struct stack* s, float value) {
     if (s->size >= STACK_SIZE) {
-        printf("Chyba: zasobnik je plny\n");
-        exit(1);
+        printf("full stack\n");
+        exit(0);
     }
     s->values[s->size++] = value;
 }
 
-// Function to pop a value from the stack
 float pop_stack(struct stack* s) {
     if (s->size == 0) {
-        printf("Chyba: zasobnik je prazdny\n");
-        exit(1);
+        printf("empty stack\n");
+        exit(0);
     }
     return s->values[--s->size];
 }
 
-// Check if input is an operator
 int is_operator(char* input) {
     return (strcmp(input, "+") == 0 || strcmp(input, "-") == 0 ||
             strcmp(input, "*") == 0 || strcmp(input, "/") == 0);
 }
 
-// Perform the operation on the top of the stack
+int is_valid_float(char* input) {
+    char* endptr;
+    strtod(input, &endptr);
+    return *endptr == '\0';
+}
+
 void perform_operation(struct stack* s, char* operator) {
     if (s->size < 2) {
-        printf("Chyba: nedostatok operandov\n");
-        exit(1);
+        printf("not enough operands\n");
+        exit(0);
     }
 
     float b = pop_stack(s);
@@ -65,13 +67,13 @@ void perform_operation(struct stack* s, char* operator) {
         result = a * b;
     } else if (strcmp(operator, "/") == 0) {
         if (b == 0) {
-            printf("Chyba: delenie nulou\n");
-            exit(1);
+            printf("division by zero\n");
+            exit(0);
         }
         result = a / b;
     } else {
         printf("Chyba: neplatna operacia\n");
-        exit(1);
+        exit(0);
     }
 
     push_stack(s, result);
@@ -82,26 +84,19 @@ int main() {
     struct stack mystack;
     mystack.size = 0;
 
-    // Reading input from stdin until EOF or an error occurs
     while (fgets(input, sizeof(input), stdin) != NULL) {
-        input[strlen(input) - 1] = '\0'; // Remove newline character
+        input[strlen(input) - 1] = '\0';
 
-        // Try to parse input as a number
-        float value;
-        if (sscanf(input, "%f", &value) == 1) {
+        if (is_valid_float(input)) {
+            float value = atof(input);
             push_stack(&mystack, value);
-        }
-        // If it's not a number, check if it's a valid operator
-        else if (is_operator(input)) {
+        } else if (is_operator(input)) {
             perform_operation(&mystack, input);
-        }
-        // Invalid input
-        else {
-            printf("Chyba: neplatny vstup\n");
-            return 1;
+        } else {
+            printf("bad input\n");
+            return 0;
         }
 
-        // Print stack after each valid input
         print_stack(&mystack);
     }