coral.cpp

//solucao de Frederico BUlhoes
#include <bits/stdc++.h>

using namespace std;

int main()
{
    int v[4];
    
    cin >> v[0] >> v[1] >> v[2] >> v[3];
    
    if (v[0] == v[2] or v[1] == v[3]) {
        
        cout << "V" << "\n";
    } else {
        cout << "F" << "\n";
    }
    
    return 0;
}