N = int(input())

import sys
if N == 1:
    print(2)
    exit()
    
for k in range(2,40):
    A = [0]
    i = 1
    while True:
        i += 1
        if i < k:
            A.append(0)
        elif i == k:
            A.append(1)
        else:
            t = 0
            for j in range(1,k + 1):
                t += A[i-j - 1]
            if t == N:
                print(k)
                exit()
            elif t > N:
                break
            A.append(t)
print(-1)