A = [int(input()) for _ in range(5)]
A = A[::-1]

dp = [1,1,2]
i = 3
while True:
    now = dp[i-1]+dp[i-2]
    if now > 10**15:
        break
    dp.append(now)
    i += 1

#print(dp)

ans = 0
if A[0] in dp:
    ans = 1
    ind = dp.index(A[0])
    for j in range(1,5):
        if A[j] == dp[ind+j]:
            ans += 1
        else:
            break
    if A[0] == 1:
        tmp = 1
        for j in range(1,5):
            if A[j] == dp[(ind+1)+j]:
                tmp += 1
            else:
                break
        ans = max(ans, tmp)
print(ans)