#include <iostream>
using namespace std;
int main (){
string str;
while(getline(cin, str)){
if(str.size() <= 8)
{cout << "NG" << endl; continue;}
int num = 0, other = 0, lower = 0, upper = 0;
bool flag = false;
for(int i = 0; i < str.size(); ++i){
if(isdigit(str[i])) num = 1;
else if(islower(str[i])) lower = 1;
else if(isupper(str[i])) upper = 1;
else other = 1;
if((num + lower + upper + other) >= 3)
{flag = true; break;}
}
if(!flag)
{cout << "NG" << endl; continue;}
for(int i = 0; i < str.size()-3; ++i){
string ss = str.substr(0,i) + str.substr(i+3);
if(ss.find(str.substr(i, 3)) != string::npos)
{flag = false; break;}
}
if(flag)
cout << "OK" << endl;
else
cout << "NG" << endl;
}
}