def -1000,999,-998,997

max_value = 1000

def calculate_parent_value(n):
    if n == 1000:
        return -999
    elif n == -1000:
        return 999
    elif n == 0:
        return 0
    else:
        return -(1 - 2*((abs(n) - 1) % 2)) * (abs(n) - 1)

for i in range(990,1001):
    print(calculate_parent_value(i))

print(calculate_parent_value(0))