import sys
input=sys.stdin.readline
def I(): return int(input())
def MI(): return map(int, input().split())
def LI(): return list(map(int, input().split()))

def main():
    mod=10**9+7
    N=I()
    #約数列挙
    def make_divisors(n):
        flag=0
        for i in range(1, int(n**0.5)+1):
            if n % i == 0:
                a=i
                b=n //i
                if i != n // i:
                    if (a-b)%2==0:
                        flag=1
                        break
                    

        return flag
    
    flag=make_divisors(N)
    
    if flag:
        print(1)
    else:
        print(-1)

        
    


main()