#include<bits/stdc++.h>
using namespace std;
using Int = long long;
//INSERT ABOVE HERE
signed main(){
  string a,b;
  cin>>a>>b;
  Int ok1=1,ok2=1;
  for(char c:a) ok1&=!!isdigit(c);
  for(char c:b) ok2&=!!isdigit(c);
  if(a.size()>1u) ok1&=a[0]!='0';
  if(b.size()>1u) ok2&=b[0]!='0';
  if(ok1) ok1&=stoll(a)<=12345;
  if(ok2) ok2&=stoll(b)<=12345;
  cout<<(ok1&&ok2?"OK":"NG")<<endl;
  return 0;
}