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

char add(double A, double B, double C,char AC){
    if(A+B==C)return printf("OK\n");
    return printf("ZLE\n"); 
}
char subtr(double A, double B, double C,char AC){
    if(A-B==C)return printf("OK\n");
    return printf("ZLE\n"); 
}
char multi(double A, double B, double C,char AC){
    if(A*B==C)return printf("OK\n");
    return printf("ZLE\n"); 
}
char divi(double A, double B, double C,char AC){
    float CC=A/B;
    if(CC==C || A/B==C)return printf("OK\n");
    return printf("ZLE\n"); 
}

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++;
}
sscanf(str,"%lF%c%lF=%lF ",&a,&ac,&b,&c);
if(ac=='+')add(a,b,c,ac);
if(ac=='-')subtr(a,b,c,ac);
if(ac=='*')multi(a,b,c,ac);
if(ac=='/')divi(a,b,c,ac);
    return 0;
}