#include <bits/stdc++.h>
#define int long long
//#define USE_FREOPEN
//#define MUL_TEST
#define FILENAME "ctrlcv"
using namespace std;
int dp[100005];

void solve() {
	int n, c, v;
	cin >> n >> c >> v;
	memset(dp, 0x3f, sizeof(dp));
	dp[1] = 0;
	for (int i = 1; i < n; i++)
		for (int j = 2; i * j < 2 * n; j++)
			dp[i * j] = min(dp[i * j], dp[i] + c + (j - 1) * v);
	int minn = 9e18;
	for (int i = n; i < 2 * n; i++) minn = min(minn, dp[i]);
	cout << minn << '\n';
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr); cout.tie(nullptr);

	#ifdef USE_FREOPEN
		freopen(FILENAME ".in","r",stdin);
		freopen(FILENAME ".out","w",stdout);
	#endif
	int _ = 1;
	#ifdef MUL_TEST
		cin >> _;
	#endif
	while (_--)
		solve();
	_^=_;
	return 0^_^0;
}