#include <bits/stdc++.h>
#define loop(n) for (int ngtkana_is_genius = 0; ngtkana_is_genius < int(n); ngtkana_is_genius++)
#define rep(i, begin, end) for(int i = int(begin); i < int(end); i++)
#define all(v) v.begin(), v.end()
#define rand(l, r) std::uniform_int_distribution<>(l, r)(mt)
#define lint long long
auto cmn = [](auto& a, auto b){if (a > b) {a = b; return true;} return false;};
auto cmx = [](auto& a, auto b){if (a < b) {a = b; return true;} return false;};
void debug_impl() { std::cerr << std::endl; }
template <typename Head, typename... Tail>
void debug_impl(Head head, Tail... tail){
  std::cerr << " " << head;
  debug_impl(tail...);
}
#ifndef STOPIT
#define debug(...)\
  std::cerr << std::boolalpha << "[" << #__VA_ARGS__ << "]:";\
  debug_impl(__VA_ARGS__);\
  std::cerr << std::noboolalpha;
#else
#define debug 0;
#endif

int main() {
  std::cin.tie(0); std::cin.sync_with_stdio(false);
  lint t, a, b;
  std::cin >> t >> a >> b;
  auto ret = (t + a - 1) / a + (t + b - 1) / b;
  auto x = std::__gcd(a, b);
  x = a / x;
  if (x <= t / b) {
    ret -= (t + x * b - 1) / (x * b);
  } else {
    ret --;
  }
  std::cout << ret << std::endl;
  return 0;
}