#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
#include <algorithm>
using namespace std;
int main()
{
	int n,a,b;
	while(cin >> n >> a >> b)
	{
	    int Min = 0x3f3f3f3f;
	    for(int i = 1;i <= n;i++)
        {
            Min = min(Min,i*a);
        }
        if(Min<n*a) Min += b;
        Min = min(Min,b);
        cout << Min << endl;
	}
	return 0;
}
