def can_go(n):
    return sum(map(int,list(n)))

N=int(input())

m=dict(zip(range(1,N+1),list(map(format,range(1,N+1),N*"b"))))
queue=[1]
Visited=[]#訪問済み
cost=[float("inf") for i in range(N)]
cost[0]=1
next_target=[]
goal=N

##print(m,goal)

while(1):
    if len(queue)==0:
        break
    target=queue[0]
    if target==goal:
        break
    next_target=[target+can_go(m[target]),target-can_go(m[target])]
    for i in next_target:
        if 1<=i and i<=N and not i in queue and not i in Visited:
            queue.append(i)
            cost[i-1]=cost[target-1]+1 
            
    queue.pop(0)
    Visited.append(target)
##    print(queue,cost)

if cost[-1]!=float("inf"):
    print(cost[N-1])
else :
    print(-1)