#include <cstdio>
#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <bitset>

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

const long long MAX = 510000;
const long long INF = 1LL << 60;
const long long MOD = 1000000007LL;

using namespace std;
typedef unsigned long long ull;
typedef  long long ll;

ll gcd(ll x, ll y)
{
	ll r;
	if (x < y) {
		swap(x, y);
	}
	while (y > 0) {
		r = x % y;
		x = y;
		y = r;
	}
	return x;
}

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


int main()
{
	ll T, A, B;
	cin >> T >> A >> B;
	ll lc = lcm(A, B);
	ll cnt = 0;
	if (T % A == 0) {
		cnt += T / A;
	}
	else {
		cnt += T / A + 1;
	}
	if (T %B == 0) {
		cnt += T / B;
	}
	else {
		cnt += T / B + 1;
	}
	if (T % lc == 0) {
		cnt -= T / lc;
	}
	else {
		cnt -= T / lc + 1;
	}
	cout << cnt << endl;
	return 0;
}