#include <bits/stdc++.h>
typedef long long ll;
typedef long double ld;
const int INF=1e9,MOD=1e9+7,ohara=1e6+10;
const ll LINF=1e18;
using namespace std;
    
#define rep(i,n) for(int (i)=0;(i)<(int)(n);(i)++)
#define rrep(i,a,b) for(int i=(a);i<(b);i++)
#define rrrep(i,a,b) for(int i=(a);i>=(b);i--)
#define all(v) (v).begin(), (v).end()
#define Size(n) (n).size()
#define Cout(x) cout<<(x)<<endl
#define doublecout(a) cout<<fixed<<setprecision(15)<<a<<endl;
#define Cerr(x) cerr<<(x)<<endl
#define fi first
#define se second
#define P pair<ll,ll> 
#define m_p make_pair
#define V vector<ll> 
#define U_MAP unordered_map<ll,ll>
#define pq priority_queue<ll>
#define rpq priority_queue<ll,vector<ll>,greater<ll>>
#define p_b push_back
    
ll n,cnt,ans,a,b,c,d,tmp,tmpp,m,h,w,x,y,sum,pos,k,q,t;
ld doua;
int dy[]={1,0,-1,0};
int dx[]={0,1,0,-1};
//int dy[]={-1,0,1,-1,1,-1,0,1};
//int dx[]={-1,-1,-1,0,0,1,1,1};
string alph("abcdefghijklmnopqrstuvwxyz"),s;
bool fl;
struct edge{int to,cost;};
    
//------ Believe yourself as a genius!!!!!! ------

long long gcd(long long aaa,long long bbb){
    if(bbb==0){
        return aaa;
    }
    return gcd(bbb,aaa%bbb);
}
 
long long lcm(long long aaa,long long bbb){
    long long g = gcd(aaa,bbb);
    return aaa/g * bbb;
}
    
int main(void){
    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(false);
    
    cin>>t>>a>>b;
    if(t%a==0)ans=t/a;
    else ans=t/a+1;
    if(t%b==0)ans+=t/b;
    else ans+=t/b+1;
    tmp=lcm(a,b);
    if(t%tmp==0)ans-=t/tmp;
    else ans-=t/tmp+1;
    Cout(max(0LL,ans));
    return 0;
}