#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using VI = vector<ll>;
using VV = vector<VI>;
using VS = vector<string>;

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define rep(i,b) FOR(i, 0, b)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl

const ll mod = 1e9 + 7;
const ll inf = 1e18;

ll gcd(ll a,ll b){
    if(b == 0) return a;
    return gcd(b,a%b);
}

ll lcm(ll a,ll b){
    ll g = gcd(a,b);
    return a / g * b;
}

ll f(ll T, ll A){
  if(T%A==0){
    return T/A;
  }else{
    return T/A + 1;
  }
}

// 重なった分
ll g(ll T, ll A, ll B){
  // c / d
  ll c = (T+A-1)/A;
  ll d = B/gcd(A,B);
  return (c+d-1)/d;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    ll T, A, B;
    cin >> T >> A >> B;

    ll ans = f(T,A) + f(T,B) - g(T,A,B);
    p(ans);
    
    return 0;
}