#include<bits/stdc++.h>

using namespace std;

typedef long long int64;
const int64 INF = 1LL << 60;


int main()
{
  int N, C, V;
  cin >> N >> C >> V;

  int64 ret = INF;
  for(int i = 1; i <= N; i++) { // コピーペーストの回数
    int64 length = 1, cost = 0, add = 0;
    for(int j = 0; j < i; j++) {
      add = length;
      length += length;
      cost += V;
      if(length >= N) break;
      cost += C;
    }
    if(length >= N) ret = min(ret, cost);
    else ret = min(ret, ((N - length) + (add - 1)) / add * V + cost);
  }

  cout << ret << endl;
}