Problem:
MathJax.Hub.Config({ tex2jax: { inlineMath: [["$","$"], ["\\(","\\)"]], processEscapes: true }});

The Maximum Number of Customers

$N$ persons visited a restaurant. The restaurant is open from 0 to $T$. The $i$-th person entered the restaurant at $l_i$ and left at $r_i$. Find the maximum number of persons during the business hours.

Constraints

$ 1 \leq N \leq 10^5 $

$ 1 \leq T \leq 10^5 $

$ 0 \leq l_i < r_i \leq T $

Input

The input is given in the following format.

$N$ $T$

$l_1$ $r_1$

$l_2$ $r_2$

:

$l_N$ $r_N$

Output

Print the maximum number of persons in a line.

Sample Input 1

6 10
0 2
1 3
2 6
3 8
4 10
5 10

Sample Output 1

4

Sample Input 2

2 2
0 1
1 2

Sample Output 2

1

Solution in C++ (judge verdict: Accepted)

#include <iostream>
using namespace std;

#define T 100000
#define MAX(X,Y) ((X)>(Y)?(X):(Y))

int main(void){
  int n,t;
  int d[T+1], ans, now;
  
  cin >> n >> t;
  for (int i=0; i<=t; i++) d[i] = 0;
  for (int i=0; i<n; i++){
    int l,r;
    cin >> l >> r;
    d[l]++; d[r]--;
  }
  now = ans = d[0];
  for (int i=1; i<=t; i++){
    now += d[i];
    ans = MAX(ans, now);
  }
  cout << ans << endl;
    
  return 0;
}