#include <stdio.h>

int main(){
    char read[1000000];
    scanf("%[^\n]", read);
    float num1, num2, answer;
    char action;
    sscanf(read, "%f %c %f %*c %f", &num1, &action, &num2, &answer);
    if(action != '/' && action != '*' && action != '-' && action != '+'){
        printf("CHYBA\n");
        return -1;
    }
    float check = (action == '/') ? num1 / num2 : (action == '*') ? num1 * num2 : (action == '+') ? num1 + num2 : num1 - num2;
    printf("%s\n", (check == answer) ? "OK" : "ZLE");

}