#include <bits/stdc++.h>
using namespace std;
const double eps = 1E-9;
const double Exp = 2.718281828459045;
const double Pi = 3.1415926535897932;
const int Max_Bit = 63;
const int INF = 2000000000;
const long long LINF = 1000000000000000007ll;
const int MOD = 1000000007;
const int NMAX = 200005;
const int MMAX = 3005;
double ff[NMAX];
int gcd(int a, int b) { return b ? gcd(b, a % b) : a; }
int main() {
  int n, m;
  double ans = 0;
  scanf("%d%d", &m, &n);
  double p1 = 0;
  for (int i = 0; i < m; ++i) {
    double p = n * log(i + 1) - n * log(m);
    if (i > 0) {
      ans += (i + 1) * (exp(p) - exp(p1));
    } else {
      ans += (i + 1) * exp(p);
    }
    p1 = p;
  }
  printf("%.15lf\n", ans);
  ;
  return 0;
}
