#include <bits/stdc++.h>
using namespace std;
void solve();
int main() {
  int m = 1;
  for (int i = 0; i < m; i++) {
    solve();
  }
  return 0;
}
long long INF = INT64_MAX;
long long mod = 1000000007LL;
vector<vector<long long> > g;
vector<long long> used;
set<long long> cur;
void solve() {
  long long n, l, v1, v2, k;
  cin >> n >> l >> v1 >> v2 >> k;
  long long s = (n + k - 1) / k;
  double tr = (double)l / v1;
  double tl = (double)l / v2;
  long double eps = 0.0000005;
  while (tr - tl > eps) {
    long double m = (long double)(tl + tr) / 2.0;
    long double t0 = (long double)(l - m * v1) / (v2 - v1);
    long double t1 = (long double)(l - m * v1) / (v2 + v1);
    if (m <= s * (t0) + (s - 1) * (t1)) {
      tl = m;
    } else {
      tr = m;
    }
  }
  printf("%.8lf", tr);
}
