def func(n):
    if n in [1,2]:
        return 1
    if memo[n] == 0:
        memo[n] = func(n-1)+func(n-2)
    return memo[n]

A = [int(input()) for _ in range(5)]
memo = [0 for _ in range(10**4)]
i = 1
ans = 0
while 1:
    if func(i) == A[4-ans]:
        ans += 1
    elif func(i) > A[0]:
        break
    i += 1
print(ans)