N = int(input())

def FF(n):
    if n%2 == 0:
        r = n//2
    else:
        r = 3*n + 1
    return r
n, i = N, 0

if n == 1:
    print(3)
    exit()
    
while (n > 1):
    n = FF(n)
    i += 1
    if i >= 10**100:
        print('infinity')
        exit()
print(i)