#include<bits/stdc++.h>
typedef long long ll;
using namespace std;
int INF = 1e9;
int MOD = 1e9+7;
int cp[50001];
int pa[50001];
main(){
    int N,C,V;
    cin >> N >> C >> V;
    fill(cp,cp+50001,INF);
    fill(pa,pa+50001,INF);
    cp[1] = C;
    pa[1] = 0;
    for(int i = 1;i <= N;i++){
        for(int j = 1;i*(j-1) <= N;j++){
            if(i+i*j > N)pa[N] = min(pa[N],cp[i]+V*j);
            else pa[i+i*j] = min(pa[i+i*j],cp[i]+V*j);
        }
        for(int j = i;j <= 50000;j++){
            cp[j] = min(cp[j],pa[j]+C);
        }
    }
    cout << pa[N] << endl;
}