#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 5;
inline int read() {
  int x = 0;
  int f = 1, hhh = getchar();
  while (!isdigit(hhh)) {
    if (hhh == '-') f = -1;
    hhh = getchar();
  }
  while (isdigit(hhh)) {
    x = x * 10 + hhh - '0';
    hhh = getchar();
  }
  return x * f;
}
int n, l, v1, v2, k;
int main() {
  n = read();
  l = read();
  v1 = read();
  v2 = read();
  k = read();
  int m = ceil(n * 1.0 / k);
  double t = 1.0 * (m - 1) * (v2 - v1) / (v1 + v2);
  double t2 = 1.0 * l / v2 / (m - t);
  double t1 = 1.0 * (l - t2 * v2) / v1;
  printf("%f\n", t1 + t2);
  return 0;
}
