//#pragma GCC optimize ("-O3","unroll-loops")
#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<queue>
#include<map>
#include<math.h>
#include<iomanip>
#include<set>
#include<numeric>
#include<cstring>
#include<cstdio>
#include<functional>
#include<bitset>
#include<limits.h>
#include<cassert>
#include<iterator>
#include<complex>
#include<stack>


#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define FOR(i, m, n) for(int i = m;i < n;i++)
#define FORR(i, m, n) for(int i = m;i >= n;i--)
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define REVERSE(v,n) reverse(v,v+n);
#define VREVERSE(v) reverse(v.begin(), v.end());
#define ll long long
#define pb(a) push_back(a)
#define m0(x) memset(x,0,sizeof(x))
#define print(x) cout<<x<<'\n';
#define pe(x) cout<<x<<" ";
#define lb(v,n) lower_bound(v.begin(), v.end(), n);
#define ub(v,n) upper_bound(v.begin(), v.end(), n);
#define int long long
#define all(x) (x).begin(), (x).end()
#define double long double

using namespace std;

int MOD = (ll)1000000000 + 7;
const ll INF = 1e17;
const double pi = acos(-1);
const double EPS = 1e-10;
typedef pair<int, int>P;
const int MAX = 200020;

int N, C, V;
int dp[200020];
signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	cin >> N >> C >> V;
	REP(i, 200000)dp[i] = INF;
	dp[1] =0;
	dp[2] = C + V;
	FOR(i, 2, 3*N+1) {
		dp[i + 1] = dp[i] + V;
	}
	FOR(i, 2, N) {
		for (int j = i * 2; j < 3 * N; j += i) {
			dp[j] =min(dp[j], dp[i] + C + V * ((j / i)-1));
		}
	}

	int ans = INF;
	FOR(i, N, 2 * N) {
		ans = min(ans, dp[i]);
	}
	print(ans);
	//REP(i, N + 1) {
	//	pe(i)print(dp[i]);
	//}
}