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



int main(){

       int i,j; 
       double number1, number2, summary,msum; 
       char operand, equ; 
       float rsum=0;
/*       char input[1000];
       char num_str[30] = {0};
       float numbers[3];
       fgets(input, 999, stdin);
       for (int i = 0, j =0; i < strlen(input); i++) {
         char c = input[i];
          if (c==' ') continue;
          if (c=='+') operand='+';
          if (c=='-') operand='-';
          if (c=='*') operand='*';
          if (c=='/') operand='/';
          if (c=='\n') break;
          if (isdigit(c)) {num_str[j++] = c - '0';}
          else if (j > 0) {
            j = 0;
            numbers[...] = atof(num_str);
          }
          }
       }
      // scanf("%lf", &number1); 
      //scanf("%lf", &number2);
      //scanf("%lf",&msum);
      

*/ 
    char* input = calloc(1000, 1);
    while (1) {
       
        input = fgets(input, 1000, stdin);
        if (input == NULL) break;
 
        fflush(stdin); 
        if (input[0] == '\n' || input[0] == EOF || strlen(input) <= 0)
            break;
 
        float values[3] = {0};
        char operation = 0;    
        
        int k = 0; 
        int num = strlen(input);
        for (int i = 0; i < num; i++) {
           
            if (input[i] == ' ')
                continue;
 
            if (isalpha(input[i]))
                break;
 
            
            if (i < strlen(input) && (isdigit(input[i]) || input[i] == '.' || (input[i] == '-' && isdigit(input[i + 1])))) {
                char temp[100] = {0}; 
                for (int j = 0; i < strlen(input) && (isdigit(input[i]) || input[i] == '.' || input[i] == '-'); j++) {
                    temp[j] = input[i++];
                }
                i--;
                
                values[k++] = (float)atof(temp);
            } else if (isdigit(input[i]) == 0 && input[i] != ' ' && input[i] != '\n' && input[i] != '=') {
                
                operation = input[i];
            }
        }
 
        
        if (k != 3) {
            printf("CHYBA\n");
            continue;
        }
 
        
        if (operation == 0 && values[1] < 0) {
            operation = '-';
            values[1] = abs(values[1]); 
        }
 
       
        float result = 0;     
      
      
      
////////////////////////////////////////////////  
      
          /*if((operand == '/') && (number2 == 0)){
                printf("Nulou sa nedá deliť");
          }
          if(operand !='+' && operand !='-' && operand !='*' && operand !='/'){
              return 1;
              printf("\n");  
          }                         
          */
          msum=values[2];
          if(operation=='+'){
                        rsum=values[0]+values[1];
                        if(msum==rsum){
                          printf("OK\n");
                        }
                        else{
                          printf("ZLE\n");
                        }
                        //printf("%lf\n",rsum);
          } 
          else if(operation=='-'){
                        rsum=values[0]-values[1];
                        if(msum==rsum){
                          printf("OK\n");
                        }
                        else{
                          printf("ZLE\n");
                        }
                        //printf("%lf\n",rsum);
          }
          else if(operation=='*'){
                        rsum=values[0]*values[1];
                        if(msum==rsum){
                          printf("OK\n");
                        }
                        else{
                          printf("ZLE\n");
                        }
                        //printf("%lf\n",rsum); 
          }
          else if(operation=='/'){
                        rsum=values[0]/values[1];
                        if(msum==rsum){
                          printf("OK\n");
                        }
                        else{
                          printf("ZLE\n");
                        }
                        //printf("%lf\n",rsum);
          }
          }
          }