SPOJ/OCubo.cpp
bool isLess(pair<int, int> a, pair<int, int> b) {
    if (a.second != b.second) {
        return a.second < b.second;
    } else {
        return a.first < b.first;
    }
}
//compare whether a is less than b from second, then first
compare whether a is less than b from second, then first
compare whether a is less than b from second then first
bool isLess(pair<int, int> a, pair<int, int> b) {
    if (a.second != b.second) {
        return a.second < b.second;
    } else {
        return a.first < b.first;
    }
}
bool isLess ( pair < int , int > a , pair < int , int > b ) { if ( a . second != b . second ) { return a . second < b . second ; } else { return a . first < b . first ; } }
compare whether a is less than b from second, then first
compare whether a is less than b from second then first