n = int(input())

for k in range(2, 65):
    A = [0 for _ in range(k - 1)] + [1]
    res = 1
    while A[-1] <= n:
        A.append(res)
        res += A[-1]
        res -= A[-k - 1]
    if n in A:
        print(k)
        exit()
print(-1)