#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  scanf("%d", &N);
  long long int L, V1, V2, K;
  scanf("%I64d %I64d %I64d %I64d", &L, &V1, &V2, &K);
  int Count = 0;
  if ((N % K) == 0) {
    Count = N / K;
  } else
    Count = (N / K) + 1;
  int count = Count - 1;
  double tmp = 1.0 + 1.0 * count * V1 * 1.0 * (2.0 / (V1 + V2)) * 1.0;
  double t1, t2;
  t1 = 1.0 * (1.0 * L * 1.0) / (tmp * V2 * 1.0);
  t2 = 1.0 * (1.0 * (L * 1.0) / V1 * 1.0) * (1.0 - 1.0 / tmp) * 1.0;
  printf("%.10f\n", t1 + t2);
  return 0;
}
