A

#include <cstdio>
#include <iostream>
#include <algorithm>

using namespace std;

int main() {
    int n, x, y, res = 0;
    cin >> n >> x >> y;

    res += min(x, y);
    n--;
    int lcm = x * y / __gcd(x, y);

    int step = lcm / x + lcm / y;
    res += n / step * lcm;

    n %= step;

    int add = int(1e9);

    for (int i = 0; i <= n; i++)
        add = min(add, max(i * x, (n - i) * y) );

    res += add;

    cout << res << endl;

    return 0;
}