func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, k;   int main() {     long long s = 0;     cin >> n >> k;     for (int i = 0; i < n; i++) {       int a, b;       cin >> a >> b;       s += b - a + 1;     }     s %= k;     if (s) s = k - s;     cout << s << endl;   }   