#U1617FS2. Why Did the Cow Cross the Road II
Why Did the Cow Cross the Road II
The long road through Farmer John's farm has N crosswalks across it, conveniently numbered 1…N (1≤N≤100,000). To allow cows to cross at these crosswalks, FJ installs electric crossing signals, which light up with a green cow icon when it is ok for the cow to cross, and red otherwise. Unfortunately, a large electrical storm has damaged some of his signals. Given a list of the damaged signals, please compute the minimum number of signals that FJ needs to repair in order for there to exist some contiguous block of at least K working signals.
INPUT FORMAT (file maxcross.in):
The first line of input contains N, K, and B (1≤B,K≤N). The next B lines each describe the ID number of a broken signal.
OUTPUT FORMAT (file maxcross.out):
Please compute the minimum number of signals that need to be repaired in order for there to be a contiguous block of K working signals somewhere along the road.
SAMPLE INPUT:
10 6 5
2
10
1
5
9
SAMPLE OUTPUT:
1