#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;

    while (fgets(line, sizeof(line), stdin) != NULL) {
        if (line[0] == '\n') {
            // Stop when the user enters a blank line
            break;
        }

        num1 = num2 = result = 0;
        op = '\0';

        // 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");
            continue;
        }

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

        // 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;
}