#include <bits/stdc++.h>
#define FOR(i,bg,ed) for(ll i=(bg);i<(ed);i++)
#define REP(i,n) FOR(i,0,n)
#define MOD 1000000007
#define int long long
using namespace std;
typedef long long ll;
typedef vector<vector<ll>> mat;
const int INF = 1e9;

int N;
int C, V;

//X:コピーの回数 Y:ペーストの回数 でN文字以上を作れるか
bool checkXY(int X, int Y)
{
    int tmp = min(X, Y);
    //int can = 1, clip = (X > 0 ? 1 : 0);
    int can = 1, clip = 0;

    REP(i,tmp) {
        can *= 2;
        clip = can / 2;
    }

    if (Y - tmp > 0) {
        can += clip * (Y - tmp);
    }

    return N <= can;
}

//vのコストで作れるか
bool checkV(int v)
{
    for (int x=1; x<=v/C; x++) {
        //if (v - C * x < 0) break;
        int y = (v - C * x) / V;

        if (checkXY(x, y)) return true;
    }

    return false;
}

signed main()
{
    cin >> N;
    cin >> C >> V;

    int lb = 0, ub = LONG_LONG_MAX;
    while (ub - lb > 1) {
        int mid = (lb + ub) / 2;
        if (checkV(mid)) ub = mid;
        else lb = mid;
    }

    cout << ub << endl;
}