#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
using ll = long long;

ll gcd(ll n, ll m) {
    if (n < m) swap(n, m);
    while (m != 0) {
        ll r = n % m;
        n = m;
        m = r;
    }
    return n;
}

int main() {
    ll t, a, b;
    cin >> t >> a >> b;

    ll g = gcd(a, b);
    ll c = a / g * b;
    if (a / g * (double)b >= t * 2) c = t;

    auto f = [t](ll a) {
        return (t + a - 1) / a;
    };

    cout << f(a) + f(b) - f(c) << endl;

    return 0;
}