1 #include<cstdio>
 2 #include<cmath>
 3 using namespace std;
 4 int main()
 5 {
 6     int n,m;
 7     while(scanf("%d %d",&n,&m)!=EOF)
 8     {
 9         double sum = 0.0;
10        double temp = n;
11         while(m--)
12         {
13             sum += temp;
14             temp = sqrt(temp);
15         }
16         printf("%.2lf\n",sum);
17     }
18     return 0;
19 }