# URL : https://yukicoder.me/problems/no/1198
n = int(input())

if n <= 20:
    for i in range(1, 2000):
        for j in range(i + 1, 2000):
            if j * j - i * i == n:
                print(1)
                exit(0)
    print(-1)
    exit(0)

if n % 2 == 0:
    if n % 4 == 0:
        print(1)
    else:
        print(-1)
else:
    print(1)