#include<iostream>
#include<regex>
using namespace std;

int main()
{
    string code;
    cin>>code;
    regex pattern("^[A-Z0-9]{4}(-[A-Z0-9]{4}){3}$);
    if(regex_match(code,pattern))
    {
        cout<<"Valid";
    }
    else
    {
        cout<<"Invaid"
    }
}