#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<sstream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<climits>
#include<cmath>
#include<string>
#include<vector>
#include<set>
#include<map>
#include<queue>
#include<numeric>
#include<functional>
#include<algorithm>
#include<bitset>
#include<tuple>
#include<unordered_set>
#include<random>
#include<array>
#include<cassert>
using namespace std;
#define INF (1<<29)
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define all(v) v.begin(),v.end()
#define uniq(v) v.erase(unique(all(v)),v.end())


int dp[20][1000];


int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);

	int n;
	int c,v;
	cin>>n>>c>>v;

	rep(i, 1000)dp[0][i] = i+1;

	rep(i,20-1)rep(j,1000)if(dp[i][j]){
		if (dp[i][j] >= n)continue;
		int len = dp[i][j];
		for (int k=1;k<c+10;k++){
			if (j+k >= 1000)break;
			dp[i + 1][j + k] = max(dp[i+1][j+k],
				dp[i][j] + len * k);
		}
	}
	int ans=INF;
	rep(i,20)rep(j,1000){
		if (dp[i][j] >= n){
			ans = min(ans, c*i+v*j);
		}
	}
	cout<<ans+ c<<endl;


	
	return 0;
}