void update(MAP & p , pii x){
MAP::iterator it = p.lower_bound(x.F), ini = it;
if( it != p.end() && it->F == x.F && it->S <= x.S) return;
if( it != p.begin() && (--it)->S <= x.S) return;
it = ini;
while( it != p.end() && it->S >= x.S) it++;
p.erase( ini, it);
p[x.F] = x.S;
}
bool napraia(pii x, const MAP & p ){
MAP::const_iterator it = p.lower_bound( x.F);
if( it == p.begin()) return true;
return (--it)->S >= x.S;
}