#include<bits/stdc++.h>
using namespace std;

#define ll long long
#define maxn 200005

ll n,p,q;

ll dp[maxn][2],g[maxn];

int main(){
	
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	
	
	freopen("money.in","r",stdin);
	freopen("money.out","w",stdout);
	
	
	cin>>n>>p>>q;
	
	g[1]=1;
	dp[1][0]=q,dp[1][1]=p;
	
	for(int i=2;i<=n;i++){
		if(dp[i-1][1]+2*p*g[i-1]<dp[i-1][0]){
			dp[i][1]=dp[i-1][1]+2*p*g[i-1]+p;
			g[i]=g[i-1]+1;
		}
		else{
			dp[i][1]=dp[i-1][0]+p;
			g[i]=1;
		}
		dp[i][0]=min(dp[i-1][1],dp[i-1][0])+q;
	}
	
	
	cout<<min(dp[n][1],dp[n][0]);
	
	
	
	
	
	return 0;
}