HDU2009

#include
#include
#include
using namespace std;
int main()
{
double sum;
int n,m;
cout<<setiosflags(ios::fixed)<<setprecision(2);
while(cin>>n>>m)
{
sum=0;
double *p=new double[m];
for(int i=0;i<m;i++)
{
if(i==0)
p[i]=n;
else
p[i]=sqrt(p[i-1]);
sum+=p[i];
}
cout<<sum<<endl;
delete[] p;
}

}