#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll md = 1000000007;
ll exp(ll a, ll b) {
  ll r = 1ll;
  while (b > 0) {
    if (b & 1) {
      r = r * (a % md);
      r = (r + md) % md;
    }
    b >>= 1;
    a = (a % md) * (a % md);
    a = (a + md) % md;
  }
  return (r + md) % md;
}
ll gcd(ll a, ll b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
template <class T>
T Min(T a, T b) {
  if (a < b) return a;
  return b;
}
template <class T>
T Max(T a, T b) {
  if (a > b) return a;
  return b;
}
string to_string(char c) { return string(1, c); }
string to_string(bool b) { return b ? "true" : "false"; }
string to_string(const char* s) { return string(s); }
string to_string(string s) { return s; }
string to_string(vector<bool> v) {
  string res;
  for (bool x : v) res += char('0' + x);
  return res;
}
template <size_t S>
string to_string(bitset<S> b) {
  string res;
  for (auto x : b) res += char('0' + x);
  return res;
}
template <class T>
string to_string(T v) {
  bool f = 1;
  string res;
  for (auto& x : v) {
    if (!f) res += ' ';
    f = 0;
    res += to_string(x);
  }
  return res;
}
void DBG() { cerr << "]" << '\n'; }
template <class H, class... T>
void DBG(H h, T... t) {
  cerr << to_string(h);
  if (sizeof...(t)) cerr << ", ";
  DBG(t...);
}
long long n, l, v1, v2, k, last = 0;
const long long Mx = 1e4 + 5;
bool check(long double t) {
  long double remtime = t, remlen = l;
  for (ll i = 1; i <= n; ++i) {
    if (remlen > remtime * v2) return false;
    long double ftime = (remlen - v1 * remtime) / (v2 - v1);
    long double btime = ftime * (v2 - v1) / (v2 + v1);
    remtime -= (ftime + btime);
    remlen -= ((ftime + btime) * v1);
  }
  return true;
}
int32_t main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cin >> n >> l >> v1 >> v2 >> k;
  n = (n + k - 1) / k;
  long double low = 0, high = (long double)l / v1, mid, ans = high;
  while (high - low > 1e-9) {
    mid = (low + high) / 2;
    if (check(mid)) {
      ans = mid;
      high = mid;
    } else
      low = mid;
  }
  cout << fixed << setprecision(12);
  cout << ans;
  cout << '\n';
  return 0;
}
