#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

int call(double A, double B, double C, char AC){
    if(AC=='/'&&B==0){
        return printf("CHYBA");;
    }
    else if(AC=='+'){
        if(A+B==C)return printf("OK");
        return printf("ZLE");
    }
    else if(AC=='-'){
        if(A-B==C)return printf("OK");
        return printf("ZLE");
    }
    else if(AC=='*'){
        if(A*B==C)return printf("OK");
        return printf("ZLE");
    }
    else if(AC=='/'){
        if(A/B==C)return printf("OK");
        return printf("ZLE");
    }    
}

int main()
{
    

char *str;
str=(char*)malloc(100);
double a,b,c;
char ac,el;
int ind=0;
for(int i=0;el!='\n';i++){
    el=getchar();
    if(isspace(el)){
        continue;
    }
    str[ind]=el;
    ind++;
}
//scanf("%s",str);
sscanf(str,"%lf%c%lf=%lf ",&a,&ac,&b,&c);
//printf("%f %d %f =%f",a,ac,b,c);
call(a,b,c,ac);
    return 0;
}