import sys

J=5
a,b=1,1
F=[a,b]
while a+b<=10**15:
    F.append(a+b)
    a,b=b,a+b

A=[]
for _ in range(J):
    A=[int(input())]+A

if A[0] not in F:
    print(0)
else:
    if A[0]==1:
        if A[1]==1:
            p=0
        else:
            p=1
    else:
        p=F.index(A[0])

    for i in range(1,J):
        if A[i]!=F[p+i]:
            print(i)
            sys.exit()
    print(J)