diff --git a/du4/program.c b/du4/program.c
index 71636b7..b4daee9 100644
--- a/du4/program.c
+++ b/du4/program.c
@@ -1,57 +1,54 @@
 #include <stdio.h>
+#include <stdbool.h>
 
-int main (){
+int main(){
+	int c[2];
+	int a, i = 0;
+	int vysledok;
 	char riadok[999];
 	char *endptr = NULL;
-	char need;
-	int i, a, vysledok = 0;
-	float c[99];
+	bool first = true;
+	bool second = false;
 	while(1){
+		a++;
 		char* r = fgets(riadok,999,stdin);
-		riadok[i++] = *r;
-		if(*r == '\n')
+		if(*r == '\n'){
 			break;
-	}
-	int j = 0;
-	do{
-		if(riadok[j] == ' '){
-			j++;
+		}else if(*r == ' ')
 			continue;
-		}else if(riadok[j] == '+'){
-			need = riadok[j];
-			j++;
+		else if(*r == '+'){
+			first = true;
+			second = true;;
 			continue;
-		}else if(riadok[i] == '/'){
-			need = riadok[j];
-			j++;
+		}else if(*r == '-'){
+			first = false;
+			second = false;
 			continue;
-		}else if(riadok[i] == '-'){
-			need = riadok[j];
-			j++;
+		}else if(*r == '/'){
+			first = true;
+			second = false;
 			continue;
-		}else if(riadok[j] == '*'){
-			need = riadok[j];
-			j++;
-			continue;
-		}else if(riadok[j] == '='){
-			if(need == '+')
-				vysledok = c[0] + c[1];
-			else if(need == '-')
-				vysledok = c[0] - c[1];
-			else if(need == '/')
-				vysledok = c[0] / c[1];
-			else if(need == '*')
-				vysledok = c[0] * c[1];
-			j++;
+		}else if(*r == '*'){
+			first = false;
+			second = true;
 			continue;
 		}else{
 			float v = strtod(riadok,&endptr);
-			c[a] = v;
-			a = a + 1;
+			c[i++] = v;
+			continue;
 		}
-	}while(j < i);
+	}
+	if(first == true && second == true)
+		vysledok = c[0] + c[1];
+	else if(first == false && second == false)
+		vysledok = c[0] - c[1];
+	else if(first == true && second == false)
+		vysledok = c[0] / c[1];
+	else if(first == false && second == true)
+		vysledok = c[0] * c[1];
 	if(vysledok == c[2])
 		printf("OK\n");
 	else
 		printf("ZLE\n");
-}
+	return 0;
+}
\ No newline at end of file