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()
    from collections import defaultdict
    dd = defaultdict(int)
    
    M=10**5+2
    for i in range(1,M):
        dd[i*i]+=1
        
    flag=0
    for i in range(1,M):
        aa=i*i
        bb=aa-N
        if dd[bb]:
            flag=1
            
    if flag:
        print(1)
    else:
        print(-1)
        
    


main()