This is the problem specification of the Milking Cows Programming Problem From USACO.
Milking Cows
Your job is to write a program that will examine a list of beginning and ending times for N (1 <= N <= 5000) farmers milking N cows and compute (in seconds):
 The longest time interval at least one cow was milked.
 The longest time interval (after milking starts) during which no cows were being milked.
PROGRAM NAME: milk2
INPUT FORMAT
Line 1:

The single integer

Lines 2..N+1:

Two nonnegative integers less than 1000000, the starting
and ending time in seconds after 0500

SAMPLE INPUT (file milk2.in)
3 300 1000 700 1200 1500 2100
OUTPUT FORMAT
A single line with two integers that represent the longest
continuous time of milking and the longest idle time.
SAMPLE OUTPUT (file milk2.out)
900 300
You can view my solution (source code) to this problem at PlanetSourceCode.com