#include <assert.h>
#include <limits.h>
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cmath>
#include <complex>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>

using ll = long long;
using P = std::pair<ll, ll>;

template <typename T1, typename T2>
std::ostream& operator<<(std::ostream& os, std::pair<T1, T2> pa) {
  return os << "[" << pa.first << ", " << pa.second << "]";
}

template <typename T>
std::ostream& operator<<(std::ostream& os, std::vector<T> vec) {
  os << "{";
  for (int i = 0; i < vec.size(); i++)
    os << vec[i] << (i + 1 == vec.size() ? "" : ", ");
  os << "}";
  return os;
}

#define rep(i, a, b) for (ll(i) = (a); i < (b); i++)
#define all(i) i.begin(), i.end()
#define debug(i) std::cerr << "debug " << i << std::endl

// const ll MOD = 998244353;
const ll MOD = 1e9 + 7;

long long extgcd(long long a,long long b,long long& x,long long& y){
  for(ll u=y=1,v=x=0;a;){
    ll q=b/a;
    std::swap(x-=q*u,u);
    std::swap(y-=q*v,v);
    std::swap(b-=q*a,a);
  }

  return b;
}

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

  ll t,a,b,temp,temp2;
  std::cin>>t>>a>>b;

  ll gcd=extgcd(a,b,temp,temp2);

  if((double)a/(double)gcd>(double)1e18/(double)b){
    std::cout<<t/a+t/b-1<<"\n";
    return 0;
  }

  ll lcm=a/gcd*b,mod=t%lcm;

  std::cout<<t/lcm*(lcm/a+lcm/b-1)+((mod!=0)?(mod/a+mod/b+1):0)<<"\n";

  return 0;
}