python
from math import cos, sin
n = cos(1) / sin(1)
for i in range(2, int(input()) + 1):
n += (cos(1) + cos(i)) / (sin(1) + sin(i))
print(n)
python
from math import cos, sin
n = cos(1) / sin(1)
for i in range(2, int(input()) + 1):
n += (cos(1) + cos(i)) / (sin(1) + sin(i))
print(n)