func_code_string: #include <bits/stdc++.h>   using namespace std;   long long n, m, k;   long long f(int x, int len) {     if (len == 0) return 0;     if (x > len)       return (long long)len * (2 * x - len - 1) / 2;     else       return (long long)x * (x - 1) / 2 + len - x + 1;   }   bool ok(int x) {     if (f(x, k - 1) + f(x, n - k) + x <= m)       return 1;     else       return 0;   }   int main() {     cin >> n >> m >> k;     int l = 1, r = 1e9;     while (r - l > 1) {       int mid = (l + r) / 2;       if (ok(mid)) {         l = mid;       } else {         r = mid;       }     }     int res = 0;     if (ok(l)) res = l;     if (ok(r)) res = r;     cout << res << endl;   }   