A = [int(input()) for _ in range(5)]
A.reverse()

fib = [1, 1]

for i in range(2, 100):
  fib.append(fib[i - 1] + fib[i - 2])

def solve(f):
  if A[0] not in f: return 0
  k = f.index(A[0])
  l = 0
  while l < 5 and f[k + l] == A[l]:
    l += 1
  return l
print(max(solve(fib), solve(fib[1:])))