#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <array>
#include <cctype>
#include <cstring>
#include <cstdlib>
#include <cassert>
#include <cmath>
#include <ctime>
#include <iomanip>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <bitset>
#include <random>
#include <utility>
#include <functional>
using namespace std;
void solve()
{
	int N,C,V;
	cin >> N >> C >> V;
	vector<long long> dp(N + 1,(long long)1e18);
	dp[1] = 0;
	for(int i = 1;i <= N;i++)
	{
		for(int j = i + i;j <= 2*N;j += i)
		{
			dp[min(j,N)] = min(dp[min(j,N)],dp[i] + C + (long long)(j / i - 1)*V);
			if(j > N) break;
		}
	}
	cout << dp[N] << endl;
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int tt = 1;
	/* cin >> tt; */
	while(tt--) solve();
}