#include "math.h"
#include <algorithm>
#include <complex>
#include <cstdio>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <vector>
#define ifor(i, a, b) for (lli i = (a); i < (b); i++)
#define rfor(i, a, b) for (lli i = (b)-1; i >= (a); i--)
#define rep(i, n) for (lli i = 0; i < (n); i++)
#define rrep(i, n) for (lli i = (n)-1; i >= 0; i--)
using namespace std;
typedef long double ld;
using lli = long long int;
int main()
{
    lli n, c, v;
    cin >> n >> c >> v;
    using p = pair<lli, pair<lli, lli>>;
    priority_queue<p, vector<p>, greater<p>> que;
    que.push(make_pair(0, make_pair(1, 0)));
    while (true) {
        auto t = que.top();
        que.pop();
        auto C = t.first;

        auto len = t.second.first;

        if (len >= n) {
            cout << C << endl;
            return 0;
        }
        auto buf = t.second.second;

        //cout << C << " " << len << " " << buf << endl;
        if (buf < len)
            que.push(make_pair(C + c, make_pair(len, len)));
        que.push(make_pair(C + v, make_pair(len + buf, buf)));
    }
}