import java.util.*;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while (sc.hasNextLine()) {
String str = sc.nextLine();
if (str.length() <= 8) {
System.out.println("NG");
continue;
}
char A = 'A', a = 'a', num = '0', other = 'O';
Set<Character> set = new HashSet<>();
for (int i = 0; i < str.length(); i++) {
if (str.charAt(i) >= 'A' && str.charAt(i) <= 'Z') {
set.add('A');
} else if (str.charAt(i) >= 'a' && str.charAt(i) <= 'z') {
set.add('a');
} else if (str.charAt(i) >= '0' && str.charAt(i) <= '9') {
set.add('0');
} else {
set.add('O');
}
}
if (set.size() < 3) {
System.out.println("NG");
continue;
}
List<String> list = new ArrayList<>();
Set<String> set1 = new HashSet<>();
for (int i = 0; i < str.length() - 2; i++) {
for (int j = i + 2; j < str.length(); j++) {
if (j == str.length() - 1){
list.add(str.substring(i));
set1.add(str.substring(i));
}else{
list.add(str.substring(i,j+1));
set1.add(str.substring(i,j+1));
}
}
}
if(list.size() == set1.size()){
System.out.println("OK");
}else{
System.out.println("NG");
}
}
}
}