// editor2
#include<iostream>
#include<regex>
using namespace std;
int main()
{
    string cardcode;
    if(!(cin>>carcode))
    return 0;
    regex pattern("^([A-Z0-9]{4}-){3}[A-Z0-9]{4}$");
    if(regex_match(carcode,pattern))
    {
        cout<<"Valid"<<endl;
    }
    else
    {
        cout<<"Invalid";
    }
    return 0;
}