#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <math.h>

bool check_spaces(const char* str) {
    int len = strlen(str);
    bool is_operator = false; 
    bool is_operand = false;  

    for (int i = 0; i < len; ++i) {
        char current_char = str[i];
        
        
        if (current_char == ' ') {
            if (!is_operator && !is_operand) {
                return false;
            }
        }
        
        else if (current_char >= '0' && current_char <= '9') {
            is_operand = true;
            is_operator = false;
        }
        
        else if (current_char == '+' || current_char == '-' || current_char == '*' || current_char == '/') {
            is_operator = true;
            is_operand = false;
        }
        
        else {
            return false;
        }
    }

    
    if (!is_operand) {
        return false;
    }

    return true;
}

char* check_math_problem(const char* problem) {
    if (!check_spaces(problem)) {
        return "ZLE";
    }

    if (strlen(problem) == 0) {
        return "CHYBA";
    }

    double n1, n2, res;
    char sing, equel;

    if(sscanf(problem, "%lf %c %lf %c %lf", &n1, &sing, &n2, &equel, &res) != 5) {
        return "CHYBA";
    }

    if (equel != '=') {
        return "CHYBA";
    }

    double result;
    switch (sing) {
        case '+':
            result = n1 + n2;
            break;
        case '-':
            result = n1 - n2;
            break;
        case '*':
            result = n1 * n2;
            break;
        case '/':
            if (fabs(n2) < 1e-9) { 
                return "ZLE";
            }
            result = n1 / n2;
            break;
        default:
            return "CHYBA";
    }

    if (fabs(result - res) < 0.01) {
        return "OK";
    } else {
        return "ZLE";
    }
}

int main() {
    char problem[100]; 

    while (true) {
        fgets(problem, sizeof(problem), stdin);
        if (strlen(problem) <= 1) { 
            break;
        }
        printf("%s\n", check_math_problem(problem));
    }

    return 0;
}