func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long n, k, f, t, sum = -999999999, m, x, i;     cin >> n >> k;     for (i = 0; i < n; i++) {       cin >> f >> t;       if (k < t) {         m = f - (t - k);       } else {         m = f;       }       x = max(sum, m);       sum = x;     }     cout << x << endl;   }   