func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     vector<vector<long long>> a;     bool tr = true;     for (long long l, r, i = 0; i < n; i++) {       cin >> l >> r;       a.push_back({l, r});     }     sort(a.begin(), a.end(),          [](const vector<long long>& a, const vector<long long>& b) -> bool {            if (a[0] == b[0]) {              return a[1] < b[1];            } else {              return a[0] < b[0];            }          });     long long f = -1, s = -1;     for (long long i = 0; i < n; i++) {       if (tr && a[i][0] > f) {         f = a[i][1];       } else if (tr && a[i][0] > s) {         s = a[i][1];       } else {         tr = false;       }     }     if (tr) {       cout <<  YES  << endl;     } else {       cout <<  NO  << endl;     }     return 0;   }   