#include<bits/stdc++.h>
#define ll long long
#define il inline
#define pn putchar('\n')
#define maxint 2147483647
#define min(x,y) (x<y?x:y)
#define max(x,y) (x>y?x:y)
#define int ll
using namespace std;
int n,k;
double l,r=1e18,mid,ans;
il bool ksm(double x,int y)
{
    if(x<=0.5)return 0;
    if(x<1.5)return n==1;
    int ret=1;
    long double t;
    for(int i=1;i<=y;i++)
    {
        t=x*ret;
        if(t>n)return 1;
        if(t-(int)t<0.5)ret=t;
        else ret=t+1;
    }
    return ret>=n;
}
signed main()
{
    #ifndef ONLINE_JUDGE
    freopen("in.txt","r",stdin);
    #endif
    scanf("%lld%lld",&n,&k);
    while(l<=r)
    {
        mid=(l+r)/2;
        if(ksm(mid,k))
            r=mid-1e-10,ans=mid;
        else
            l=mid+1e-10;
    }
    printf("%.12lf\n",ans);
    return 0;
}