#include using namespace std; bool cmp(pair a, pair b) { return a.first == b.first ? a.second < b.second : a.first < b.first; } int main() { int n; pair p[200005]; cin >> n; for(int i = 0 ; i < n ; i++) { cin >> p[i].first >> p[i].second; } sort(p, p+n, cmp); int tv1 = -1, tv2 = -1; for(int i = 0 ; i < n ; i++) { if(p[i].first > tv1) { tv1 = p[i].second; } else { if(p[i].first > tv2) { tv2 = p[i].second; } else { cout << "NO" << endl; return 0; } } } cout << "YES" << endl; return 0; }