func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int a, b, n, m, ar[200] = {0}, tp = 1;     cin >> n >> m;     for (int i = 1; i <= n; i++) {       cin >> a >> b;       for (int j = a + 1; j <= b; j++) {         if (!ar[j]) tp++, ar[j]++;       }     }     cout << ((tp == m + 1) ?  YES  :  NO ) << endl;     return 0;   }   