#!/usr/bin/python

from string import find

def news_date_pool(pool, begin_date, end_date):
	for item in pool:
		if item[1].find(begin_date) != -1 :
			first=item[0]
			break
	for item in pool:
		if item[1].find(end_date) != -1:
			last=str(int(item[0])-1)
			break
	date_string=first+'-'+last
	return date_string

def threadstats(array):
	subjects=[]
	stats=[]
	for item in array:
		if item[1] not in subjects:
			subjects.append(item[1])
			stats.append(1)
		else:
			ar_index=subjects.index(item[1])
			stats[ar_index]=stats[ar_index]+1
	out=map(None, stats, map(None, subjects))
	out.sort()
	return out