Rock of Advice
– Who goes there? – asked Fao (in the jungle, this question is always asked after the trumpet has sounded). – Dholes, dholes, the Deccan dholes! The red killer dogs! They are coming from the south, saying there is no game in the Deccan.
On this day, wolves from the large Seeonee pack, along with members from neighboring tribes of the Free People, gathered at the Council Rock. Some stayed at the rock for extended periods, while others quickly departed on their tasks. Everyone was busy preparing and discussing the upcoming battle with the red dogs – the Deccan dholes.
The injured Won-tolla, a lone wolf who brought news of the red dogs' approach, lay in the shade of a large tree, trying to regain strength before the decisive battle. To gauge the Seeonee pack's chances, Won-tolla began noting the arrival and departure times of everyone who came to the Council Rock.
What was the maximum number of wolves present at the Council Rock at the same time?
Input
The first line contains the number n (n ≤ 10^5) - the number of wolves who visited the Council Rock that day. The next n lines each contain the arrival and departure time of a wolf. It is assumed that a wolf was at the Council Rock from the moment of arrival until the moment of departure, inclusive. All input numbers are between 0 and 1000.
Output
Output the maximum number of wolves that were simultaneously present at the Council Rock.