#include <cstdio>
#include<iostream>
#include<cmath>
#include<cstring>
#include<string>
#include<algorithm>
#include<map>
using namespace std;
const int MAXN = 1e5+5;
int n,m;
double dp[MAXN];
int main()
{
cin>>n>>m;
dp[1] = 1;
for(int i = 2;i <= m;i++)
{
dp[i] = dp[i-1]+1-dp[i-1]/n;
}
printf("%.10lf\n",dp[m]);
return 0;
}