#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define MT make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define rt return
using dbl = double;
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;

const ll INF = LLONG_MAX / 3;

ll f[50001];

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

    ll N, C, V;
    cin >> N >> C >> V;
    rep(i, N + 1)f[i] = INF;

    f[1] = C;

    ll ans = INF;
    for (int i = 1; i <= N; ++i){
        smin(ans, (N - 1) / i * V + f[i]);
        for (int j = 1; i + j*i <= N; ++j) {
            smin(f[i+j*i], j * V + f[i] + C);
        }
    }
    cout << ans << endl;
}