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

const ll inf = 1e10;
ll ans = inf;
ll n, c, v;

void dfs(ll num, ll cNum, ll cost) {
    if (num >= n) {
        ans = min(ans, cost);
        return;
    }
    dfs(num + cNum, cNum, cost+v);
    dfs(num + num, num, cost+c+v);
}

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

    cin >> n >> c >> v;

    dfs(1, 1, c);
    cout << ans << endl;

    return 0;
}