Imanol-Mikel Barba Sabariego / euler · Files

#!/usr/bin/python

import sys;
import math;

lim = 1000000
maxLength = 0
maxChain = 0

def collatz(num):
	counter = 1
	while(num is not 1):
		if(num % 2 == 0):
			num /= 2
		else:
			num = num*3 + 1
		counter += 1
	return counter

for i in range(1,lim):
	length = collatz(i)
	if(length > maxLength):
		maxLength = length
		maxChain = i

print maxChain