#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
#define rep(i,s,e) for(int (i) = (s);(i) <= (e);(i)++)

int N,C,V;

vector<int> dp(101010,1e9);
int main(){
  dp[1] = 0;
  cin >> N >> C >> V;

  rep(i,1,N - 1){
    for(int j = 1;i + i * j <= 101010 - 1;j++){
      dp[i + i * j] = min(dp[i + i * j] , dp[i] + C + V * j);
    }
  }

  int ans = dp[N];

  rep(i,N,101010 - 1){
    ans = min(ans , dp[i]);
  }

  cout << ans << endl;
}