#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < n; i++)
#define repb(i, a, b) for(int i = a; i >= b; i--)
#define all(a) a.begin(), a.end()
#define o(a) cout << a << endl
#define int long long
using namespace std;
typedef pair<int, int> P;

const int INF = 1e12;
int dp[100010];

signed main(){
	int n, c, v;
	cin >> n >> c >> v;
	rep(i, 0, 100010) dp[i] = INF;
	dp[1] = 0;
	rep(i, 1, 2 * n + 5){
		for(int j = 2 * i; j <= 2 * n + 5; j += i){
			dp[j] = min(dp[j], dp[i] + c + ((j / i) - 1) * v);
		}
	}
	// rep(i, 1, n + 1){
	// 	cout << i << " " << dp[i] << endl;
	// }
	int ans = INF;
	rep(i, n, 2 * n + 5) ans = min(ans, dp[i]);
	cout << ans << endl;
}