Var X,p,s,i,n:integer;
F:real;
Begin
Read(x,n);
For i:=1 to n do
P:=p*x;
S:=s+i;
F:=f+p/s
End;
Write(f);
End.
P=1
S=0
F=0
N= int(input())
x= int(input())
for i in range(1,N):
P=P*x
S=s+i
print(f)
