#include <bits/stdc++.h>
int a[10001];
bool check(int n) {
  for (int i = 2; i <= n; i++) {
    if (abs(a[i] - a[i - 1]) > 1) {
      return false;
    }
  }
  return true;
}
using namespace std;
int main() {
  long long n, m, k;
  cin >> n >> m >> k;
  long long ans = m - n;
  if (ans == 0) {
    cout << 1 << endl;
    return 0;
  }
  if (ans == 1) {
    cout << 2 << endl;
    return 0;
  }
  ans--;
  long long t = 2;
  long long left = k - 1;
  long long right = k + 1;
  while (ans > 0) {
    long long r1 = 0, r2 = 0;
    if (left > 0) {
      r1 = k - left;
      left--;
    } else {
      r1 = k - 1;
    }
    if (n - right > 0) {
      r2 = right - k;
      right++;
    } else {
      r2 = n - k;
      if (r1 == k - 1) {
        cout << (ans / (r1 + r2 + 1)) + t << endl;
        return 0;
      }
    }
    if (r1 + r2 + 1 <= ans) {
      t++;
      ans -= r1 + r2 + 1;
    } else {
      cout << t << endl;
      return 0;
    }
  }
  cout << t << endl;
  return 0;
}
