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

int main() {
    char line[100];
    double num1, num2, result, expected_result;
    char op;

    // Read the input line
    fgets(line, sizeof(line), stdin);

    // Remove any spaces between symbols
    for (int i = 0; line[i] != '\0'; i++) {
        if (isspace(line[i])) {
            for (int j = i; line[j] != '\0'; j++) {
                line[j] = line[j + 1];
            }
            i--; // Move back one step to recheck the current character
        }
    }

    // Parse the line
    sscanf(line, "%lf%c%lf=%lf", &num1, &op, &num2, &expected_result);

    // Check if the input is valid
    if (op != '+' && op != '-' && op != '*' && op != '/') {
        printf("CHYBA\n");
        return 1;
    }

    // Check for division by zero
    if (op == '/' && num2 == 0) {
        printf("ZLE\n");
        return 0;
    }

    // Perform the calculation
    switch (op) {
        case '+':
            result = num1 + num2;
            break;
        case '-':
            result = num1 - num2;
            break;
        case '*':
            result = num1 * num2;
            break;
        case '/':
            result = num1 / num2;
            break;
    }

    // Check if the result is correct
    if (result == expected_result) {
        printf("OK\n");
    } else {
        printf("ZLE\n");
    }

    return 0;
}