Python
def math():
n = int(input())
i = 0
while i != n:
i = i + 1
S = ((-1)**(i + 1)) / (2 * i - 1)
print(S)
math()
Python
def math():
n = int(input())
i = 0
while i != n:
i = i + 1
S = ((-1)**(i + 1)) / (2 * i - 1)
print(S)
math()