func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     long long n, m;     cin >> n >> m;     if (m == 0) {       cout << 1 << endl;       return 0;     }     if (m <= n / 2) {       cout << m << endl;     } else {       long long res = n - m;       cout << res << endl;     }     return 0;   }   