N = int(input())

S = set()
ans = 0
flag = False
while not flag or (N != 1 and N not in S):
    flag = True
    S.add(N)
    ans += 1
    if N%2 == 0:
        N //= 2
    else:
        N = 3*N+1

print(ans if N == 1 else "infinity")