memo = {}
def f(n):
    if n==0:
        return 1
    if n==1:
        return 1
    if n in memo:
        return memo[n]
    memo[n]=f(n-1)+f(n-2)
    return memo[n]
B = []
for i in range(75):
    B.append(f(i))
A = [int(input()) for _ in range(5)]
A = A[::-1]
cmax = 0
for i in range(75-5+1):
    cnt = 0
    for j in range(i,i+5):
        if B[j]==A[j-i]:
            cnt += 1
        else:break
    cmax = max(cmax,cnt)
print(cmax)