import math
n=int(input())
if n%2==1:
    if n==1:
        print(-1)
    else:
        print(1)
else:
    if math.sqrt(n)==int(math.sqrt(n)):
        print(-1)
    else:
        num1=n//2
        if num1-1>0 and (num1-1)%2==1:
            print(1)
        else:
            print(-1)