#include <bits/stdc++.h>
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define FORR(i,a,b) for (int i=(a);i>=(b);i--)
#define pb push_back

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef set<int> si;
const int inf = 1e9;
const int mod = 1e9+7;

ll pow(ll a, ll n){
  ll p = 1;
  while(n > 0){
    if(n & 1) p = p * a;
    a = a * a;
    n >>= 1;
  }
  return p;
}
int n, c, v;
main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin >> n >> c >> v;
  int ans = inf;
  FOR(i, 1, 20){
    int p = 2, pr = 1, ps = 0;
    while(pow(p, i) < n) p++;
    FOR(j, 0, i){
      if(pr * pow(p-1, i-j) < n){
        ps += p;
        pr *= p;
      }else{
        ps += p-1;
        pr *= p-1;
      }
    }
    int co = i * c + (ps - i) * v;
    ans = min(ans, co);
  }
  cout << ans << endl;
}