#include "bits/stdc++.h"

using namespace std;

#define _CRT_SECURE_NO_WARNINGS
#define rep(i,s,l) for(ll i=s;i<l;i++)
#define rev_rep(i,l,s) for(ll i=l;i>=s;i--)
#define all(x) (x).begin(), (x).end()
#define uniq(v) v.erase( unique(v.begin(), v.end()), v.end() );

using ll = long long; using ld = long double;
using P = pair<ll, ll>; using VP = vector<P>;
using VI = vector<int>; using VLL = vector<ll>; using VS = vector<string>; using VC = vector<char>;

const int INF = 2147483647;
const ll LINF = 1152921504606846976;
const ll MOD = 1e9 + 7;
const ld EPS = 1e-9;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
ll gcd(ll p, ll q) { while (q) { ll t = p % q; p = q; q = t; } return p; }
ll lcm(ll a, ll b) { return a * b / gcd(a, b); }
inline ll mod(ll x, ll y) { if (x >= y) { return x % y; } else if (x < 0) { return (x % y + y) % y; } else { return x; } }

signed main()
{
	const streamsize PRECISION_SIZE = 15;
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	std::cout << std::fixed << std::setprecision(PRECISION_SIZE);
	
	int d;
	int a, b;
	cin >> d;
	cin >> a >> b;
	
	ll minv{ INF };
	rep(x, 0, d + 1) {
		chmin(minv, x * a + (d - x) * b);
	}

	cout << minv << "\n";

	return EXIT_SUCCESS;
}