func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m, l, r, cnt;   int a[105];   int main() {     cin >> n >> m;     for (int i = 0; i < n; ++i) {       cin >> l >> r;       for (int i = l; i <= r; ++i) {         a[i] = 1;       }     }     for (int i = 1; i <= m; ++i) {       if (!a[i]) cnt++;     }     cout << cnt << endl;     for (int i = 1; i <= m; ++i) {       if (!a[i]) cout << i <<    ;     }     cout << endl;     return 0;   }   