#include <bits/stdc++.h>
inline void inp(long long int &n) {
  n = 0;
  int ch = getchar();
  int sign = 1;
  while (ch < '0' || ch > '9') {
    if (ch == '-') sign = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9')
    n = (n << 3) + (n << 1) + ch - '0', ch = getchar();
  n = n * sign;
}
long long int add(long long int a, long long int b) {
  return a + b - (a + b >= 1000000007) * 1000000007;
}
long long int sub(long long int a, long long int b) {
  return a - b + (a - b < 0) * 1000000007;
}
long long int mult(long long int a, long long int b) {
  return (1LL * a * b) % 1000000007;
}
inline long long int gcd(long long int a, long long int b) {
  long long int t;
  while (b) {
    a = a % b;
    t = a;
    a = b;
    b = t;
  }
  return a;
}
long long int exponentmod(long long int a, long long int b) {
  long long int res = 1;
  a %= 1000000007;
  assert(b >= 0);
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % 1000000007;
    a = a * a % 1000000007;
  }
  return res;
}
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  double n, l, v1, v2, k;
  cin >> n >> l >> v1 >> v2 >> k;
  long long int z = ceil(1.0 * n / k);
  double temp = z - 1;
  temp *= (v2 - v1);
  temp /= 1.0 * (v2 + v1);
  temp = 1.0 * z - temp;
  double p = 1.0 * l / temp;
  double ans = 1.0 * p / v2;
  ans += 1.0 * (l - p) / v1;
  cout << fixed << setprecision(9) << ans << endl;
  return 0;
}
