while(<>){
    chomp;
    next if $. == 1;
    /^[_\.]\d+[a-zA-Z]*_?$/ ? print "VALID\n" : print "INVALID\n";

import java.io.*;
import java.util.*;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
public class Solution {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n=Integer.parseInt(scanner.nextLine());
        Pattern pattern = Pattern.compile("^[_\\.]\\d+[a-zA-Z]*_?$");
        for(int i=0;i<n;i++)
        {   Matcher matcher = pattern.matcher(scanner.nextLine());
            if (matcher.find()) System.out.println("VALID");
            else    System.out.println("INVALID");
        }
    }
}

import re

regex = re.compile(r'^[_\.]\d+[a-zA-Z]*_?$')

n = int(input())
for _ in range(n):
    print('VALID' if regex.match(input()) else 'INVALID')

import re
pattern = "^((_|\.)[0-9]+[a-zA-Z]*_?)$"

for _ in range(int(input())) :
    string = input()
    if re.search(pattern ,string) :
        print("VALID")
    else:
        print("INVALID")

import re
for _ in range(int(input())):
    regex = re.compile(r"[_.]\d+[a-zA-Z]*_?$")
    print("VALID" if regex.match(input()) else "INVALID")