#include <stdio.h>

int main(){
	float a,b,v;
	int o,p;
	scanf("%f",&a);
	while((o=getchar())==' '){
	}
	scanf("%f",&b);
	while((p=getchar())==' '||(p=getchar())=='='){
	}
	scanf("%f",&v);
	switch(o){
		case '+':if(v==(a+b)){
				printf("OK\n");
			  }else{
				printf("ZLE\n");
			}
			break;
		case '-':if(v==(a-b)){
				printf("OK\n");
			  }else{
				printf("ZLE\n");
			}
			break;
		case '*':if(v==(a*b)){
				printf("OK\n");
			  }else{
				printf("ZLE\n");
			}
			break;
		case '/':if(v==(a/b)&&b!=0){
				printf("OK\n");
			  }else{
				printf("ZLE\n");
			}
			break;
		default: printf("CHYBA\n");
			break;
		}
return 0;
}