#include<iostream>

using namespace std;

bool Alp(string s){

   bool ret=false;
   for(int i=0; i<s.size(); i++){
      ret|=(('a'<=s[i]&&s[i]<='z')||('A'<=s[i]&&s[i]<='Z'));
   }
   return ret;
}

bool Zero(string s){

   if(s.size()==1) return false;
   if(s[0]=='0') return true;
   else return false;

}

int main(){

   string A, B;
   cin>> A>> B;

   if(Alp(A)||Alp(B)){
      cout<< "NG"<< endl;
      return 0;
   }
   if(Zero(A)||Zero(B)){
      cout<< "NG"<< endl;
      return 0;
   }
   if(stoi(A)<=12345&&stoi(B)<=12345){
      cout<< "OK"<< endl;
   }else{
      cout<< "NG"<< endl;
   }

   return 0;
}