diff --git a/cv3/program.c b/cv3/program.c
index 6664f3a..b64bce6 100644
--- a/cv3/program.c
+++ b/cv3/program.c
@@ -1,3 +1,4 @@
+#include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -46,13 +47,14 @@ int main() {
     while (fgets(bufer, sizeof(bufer), stdin) != NULL) {
         char* konec;
         double chislo = strtod(bufer, &konec);
+        if (chislo == 0 && strcmp(bufer, "0\n") != 0) {
+            printf("bad input\n");
+            exit(1);
+        }
         if (*konec == '\n' && *bufer != '\n' && *bufer != ' ') {
-            if (konec - bufer == 1) {
-                printf("bad input\n");
-                exit(1);
-            }
             push(&stek, chislo);
         } else if (strcmp(konec, "+\n") == 0) {
+
             if (isEmpty(&stek)) {
                 printf("no input\n");
                 exit(1);
@@ -106,6 +108,9 @@ int main() {
                 exit(1);
             }
             push(&stek, a / b);
+        } else if (isalpha(konec[-1])) {
+            printf("bad input\n");
+            exit(1);
         } else {
             printf("bad input\n");
             exit(1);