#include<stdio.h>
#include<math.h>
struct try
{
  double number1;
  char sign;
  double number2;
  double final;
};
void ok();
void zle();
int main(){
struct try y1[20];
int idx =0;
while (5){
  int r = scanf("%lf", &y1[idx].number1);
       if (r == -1){
           break;
       }
  scanf(" %c ", &y1[idx].sign);
  scanf("%lf", &y1[idx].number2);
  scanf(" = %lf",&y1[idx].final);
  idx=idx+1;
}
int nikita=0;
while (nikita < idx){
        idx=idx+1;
  if(y1[nikita].sign == '+'){
    if (round((y1[nikita].number1 + y1[nikita].number2)*100)/100 == y1[nikita].final)
    {
      ok();
      break;
    } else{
      zle();
      break;
    }
  }
  if(y1[nikita].sign == '-'){
    if (round((y1[nikita].number1 - y1[nikita].number2)*100)/100 == y1[nikita].final){
        ok();
        break;
    } else{
        zle();
        break;
    }
  }
  if(y1[nikita].sign == '*'){
    if (round(y1[nikita].number1 * y1[nikita].number2 * 100) / 100 == y1[nikita].final)
    {
        ok();
        break;
    } else
    {
      zle();
      break;
    }
    
  }
  if(y1[nikita].sign == '/'){
    if (round(y1[nikita].number1 / y1[nikita].number2 * 100) / 100 == y1[nikita].final)
    {
      ok();
      break;
    } else{
      zle();
      break;
        } 
  }
}
  return 0;
}
void ok(){
        printf("OK\n");
}
void zle(){
      printf("ZLE\n");  
}