模拟

import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(System.out);

        String str = null;
        while ((str = br.readLine()) != null) {
            pw.println(judge(str) ? "OK" : "NG");
        }

        pw.flush();
        pw.close();
        br.close();
    }

    private static boolean judge(String str) {
        int n = str.length();
        // 条件1：长度超过8位
        if (n <= 8) {
            return false;
        }

        // 条件2：包括大小写字母.数字.其它符号,以上四种至少三种
        int hasUpper = 0, hasLower = 0, hasDigit = 0, hasOther = 0;
        for (char c : str.toCharArray()) {
            if (Character.isUpperCase(c)) {
                hasUpper = 1;
            } else if (Character.isLowerCase(c)) {
                hasLower = 1;
            } else if (Character.isDigit(c)) {
                hasDigit = 1;
            } else {
                hasOther = 1;
            }
        }
        if (hasUpper + hasLower + hasDigit + hasOther < 3) {
            return false;
        }

        // 条件3：不能有长度大于2的包含公共元素的子串重复
        for (int i = 0; i < n - 3; i++) {
            String pattern = str.substring(i, i + 3);
            if (str.lastIndexOf(pattern) != i) {
                return false;
            }
        }
        return true;
    }
}