#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using pi = pair<int, int>;
const int mod = 998244353;
const ll inf = ll(1e18);
const double PI = acos(-1), eps = 1e-9;
double fast_pow(double a, int p) {
  double res = 1;
  while (p) {
    if (p % 2 == 0) {
      a = a * a;
      p /= 2;
    } else {
      res = res * a;
      p--;
    }
  }
  return res;
}
const int mxn = 1e5, mxa = 5e3;
int m, n;
void solve() {
  cin >> m >> n;
  double ans = 0, p = 1.0 / m;
  for (int i = 1; i <= m; ++i) {
    double temp = fast_pow(p * i, n) - fast_pow(p * (i - 1), n);
    ans += temp * i;
  }
  cout << setprecision(20) << ans << '\n';
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int t;
  t = 1;
  while (t--) solve();
}
