diff --git a/du4/program.c b/du4/program.c
index 4bc46de..10e0b95 100644
--- a/du4/program.c
+++ b/du4/program.c
@@ -15,17 +15,19 @@ int main(){
     char* ptr;
     bool equals = false;
 
-    for(int i = 0; fgets(input, 100, stdin); i++){
+    for(int i = 0; fgets(input, 100, stdin) != NULL; i++){
         counter = 0;
         operation = 0;
         equals = false;
         memset(number1, '\0', 25);
         memset(number2, '\0', 25);
 
-        while (input[counter] != '\0'){
+        while (input[counter] != '\0' && input[counter] != '\n'){
             symbol = input[counter++];
             while(isspace(symbol))
                 symbol = input[counter++];
+            if(symbol == '\0' || symbol == '\n')
+                break;
             switch(symbol){
                 case '+':
                     operation = 1;