#include using namespace std; typedef long long ll; #define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++) #define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++) #define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--) #define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--) #define all(x) (x).begin(), (x).end() #define sz(x) ((ll)(x).size()) #define len(x) ((ll)(x).length()) ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; } ll lcm(ll a, ll b) { return a / gcd(a, b) * b; } int main() { cin.tie(0); ios::sync_with_stdio(false); // ifstream in("input.txt"); // cin.rdbuf(in.rdbuf()); ll t, a, b; cin >> t >> a >> b; ll cnt1 = (t - 1) / a + 1; ll cnt2 = (t - 1) / b + 1; ll cnt3 = (t - 1) / lcm(a, b) + 1; ll ans = cnt1 + cnt2 - cnt3; cout << ans << endl; return 0; }