s,a,b=0,[],[]
for i in range(int(input())):a.append(input())
for x in a:
    for j in range(int(x)):s+=pow(-1,int(j))/((2*int(j))+1)
    b.append(s)
    s=0
for i in b:print("{0:.15f}".format(i))

b=[]
for i in range(int(input())):
    s=sum([pow(-1,j)/(2*j+1) for j in range(int(input()))])
    b.append("{0:.15f}".format(s))
for x in b:print(b)

for x in ["{0:.15f}".format(sum([pow(-1,j)/(2*j+1) for j in range(int(input()))])) for i in range(int(input()))]:print(x)