from functools import reduce
a = []
c = []
def Even(n):
for i in range(1,n+1):
if i % 2 == 0:
a.append(1/i)
else:
continue
b = reduce(lambda x,y:x+y,a)
return b
def Odd(n):
for i in range(1,n+1):
if i % 2 == 0:
continue
else:
c.append(1/i)
d = reduce(lambda x,y:x+y,c)
return d
if __name__ == '__main__':
n = int(input('请输入任意数字:'))
if n == 0 :
print('请重新输入!')
elif n < 0:
print('请重新输入!')
elif n % 2 == 0:
print(Even(n))
else:
print(Odd(n))