#include <bits/stdc++.h>
using namespace std;
template <typename T>
void trace(const char* name, T&& arg1) {
  cout << name << " : " << arg1 << endl;
}
template <typename T, typename... Args>
void trace(const char* names, T&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cout.write(names, comma - names) << " : " << arg1 << " | ";
  trace(comma + 1, args...);
}
const long long MOD = 1000 * 1000 * 1000 + 7;
const long long NMAX = 10000 * 1000 + 111111;
void solve() {
  long long n, k, tripsFor, tripsBac;
  long double l, v1, v2, x, time;
  cin >> n >> l >> v1 >> v2 >> k;
  tripsFor = (long long)((n + k - 1) / k);
  tripsBac = tripsFor - 1;
  time = ((tripsFor / (v2 - v1)) + (tripsBac / (v2 + v1)));
  x = l / (v1 * time + 1);
  cout << fixed << setprecision(10) << (l - x) / v1 << "\n";
  return;
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long t = 1;
  while (t--) {
    solve();
  }
}
