#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

template<typename T>
inline T gcd (T a, T b)
{
  if (a < 0) a = -a;
  if (b < 0) b = -b;
  if (a < b) std::swap(a, b);
  while (b)
  {
    a %= b;
    std::swap(a, b);
  }
  return a;
}

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