#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define all(x) (x).begin(),(x).end()
const int mod=1000000007,MAX=100005;
const ll INF=1LL<<60;

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

int main(){

    ll T,A,B;cin>>T>>A>>B;
    ll ans=(T+A-1)/A+(T+B-1)/B;
    if(log(A)+log(B)-log(gcd(A,B))>=log(T)) cout<<ans-1<<endl;
    else cout<<ans-(T+A/gcd(A,B)*B-1)/(A/gcd(A,B)*B)<<endl;
}