N=int(input())

a=list(range(1,N+1))
b=[]
c=[[1,1]]
d=[]
e=[]

for i in range(1,N+1):
    b.append(int(bin(i).count('1')))
    
for i in c:
    if ((a[i[0]-1]+b[i[0]-1])in a)and(((a[i[0]-1]+b[i[0]-1])in e)==False):
        c.append([a[i[0]-1]+b[i[0]-1],i[-1]+1])
    if ((a[i[0]-1]-b[i[0]-1])in a)and(((a[i[0]-1]-b[i[0]-1])in e)==False):
        c.append([a[i[0]-1]-b[i[0]-1],i[-1]+1])
    e.append(a[i[0]-1])
    d.append([a[i[0]-1],i[-1]])

if N in e:
    print(c[e.index(N)][-1])
else:
    print(-1)