def getChainLength(number):
    result = 1

    while number!=1:
        number =  number/2 if number & 1==0 else 3*number+1
        result+=1

    return result



maxNumber = 0
maxLength = 0

for i in range(1,100000):
    currLength = getChainLength(i)
    if currLength>maxLength:
        maxLength = currLength
        maxNumber = i

print "number: %d; length: %d" % (maxNumber, maxLength)