#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:66777216")
using namespace std;
int n, L, v1, v2, k;
void solve() {
  cin >> n >> L >> v1 >> v2 >> k;
  int q = (n + k - 1) / k;
  long double val =
      ((1 + (long double)(v2 - v1) / (v2 + v1)) * (q - 1)) * v1 + v2;
  long double t = L / val;
  long double res = t + (long double)(L - t * v2) / v1;
  cout << res << endl;
}
void testgen() {
  FILE* f = fopen("input.txt", "w");
  fclose(f);
}
int main() {
  std::cout << std::fixed;
  std::cout.precision(8);
  std::cerr << std::fixed;
  std::cerr.precision(3);
  solve();
  return 0;
}
