#include <iostream>
#include <algorithm>
#include <vector>
#include <string>

using namespace std;

long long n, c, v;

long long f(int len, int clip) {
  if (len >= n) return 0;
  if (clip == 0) return f(len, len);
  return min(f(len + len, len) + len + clip, f(len + clip, clip) + clip);
}

int main() {
  cin >> n >> c >> v;
  cout << f(1, 0) << endl;
}