// editor2
#include<iostream>
using namespace std;
int main()
{
    string s;
    cin >> s;
    if(s.length() != 14){
        cout<"Invalid";
        return 0;
    }
    for (int i=0;i<14;i++){
        if(i == 4|| i ==9){
            if(s[i] !='-'){
                cout<<"Invalid";
                return 0;
            }
        }
        else{
            if(!((s[i]>='A' && s[i]<='Z'||(s[i] >='0' && s[i]<='9'))){
                cout<<"Invalid";
                return 0;
            }
        }
    }
    cout<<"valid";
    return 0;
}