#include <bits/stdc++.h>
using namespace std;
double ppow(double a, int b) {
  if (b == 1) return a;
  if (b == 0) return 1;
  double y = ppow(a, b / 2);
  y = y * y;
  if (b % 2 == 1) y = y * a;
  return y;
}
int main() {
  int n, m, i;
  double s = 1, ans = 0, c = 0, x;
  scanf("%d%d", &n, &m);
  for (i = 1; i <= m; i++) s = s / n;
  for (i = 1; i <= n; i++) {
    x = (double)i / n;
    x = ppow(x, m);
    ans += (x - c) * i;
    c = x;
  }
  printf("%.8lf\n", ans);
  return 0;
}
