#include<bits/stdc++.h>
using namespace std;
#define int long long
#define mid (l + r) / 2
int k, cnt;
long double n, ans, eps = 0.000000001;
inline int check(long double x){
	long double ans = 1;
	for(int i = 1 ; i <= k ; ++i){
		ans = (floor)(ans * x + 0.5); 
		if(ans > n - eps) return 1;	
	}
	return 0;
}
signed main(){
	cin >> n >> k, ans = n;
	cout << fixed << setprecision(10);
	if(n == 1){
		printf("0.5");
		return 0;
	}
	if(k > 10000){
		printf("1.5");
		return 0; 
	}
	if(k == 1){
		cout << n - 0.5;
		return 0; 
	}
	long double l = 1, r = min(n, (long double)1e10); 
	while(l <= r - eps && cnt <= 1000){
		if(check(mid)) ans = min(ans, mid), r = mid;
		else l = mid;
		++cnt;
	}
	cout << ans;
	return 0;
}