#include <bits/stdc++.h>
using namespace std;

struct CumulativeSum{
    vector<int> data;
    CumulativeSum(int sz) : data(sz, 0) {};
    void add(int k, int x){
        data[k] += x;
    }
    void build(){
        for(int i = 1; i < data.size(); i++){
            data[i] += data[i - 1];
        }
    }
    //区間[0,k]の和
    int query(int k){
        if(k < 0) return 0;
        return (data[min(k, (int)data.size() - 1)]);
    }
    //区間[l.r)の和
    int query(int l, int r){
        return query(r - 1) - query(l - 1);
    }
};

int main(){
    int n, t;
    cin >> n >> t;
    CumulativeSum cs(t + 1);
    for(int i = 0; i < n; i++){
        int l, r;
        cin >> l >> r;
        cs.add(l, 1);
        cs.add(r, -1);
    }
    cs.build();
    int ans = 0;
    for(int i = 0; i <= t; i++){
        ans = max(ans, cs.query(i));
    }
    cout << ans << endl;
}

### Prompt

Develop a solution in cpp to the problem described below:

$N$ 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.

Examples

Input

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


Output

4


Input

2 2
0 1
1 2


Output

1

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;

struct CumulativeSum{
    vector<int> data;
    CumulativeSum(int sz) : data(sz, 0) {};
    void add(int k, int x){
        data[k] += x;
    }
    void build(){
        for(int i = 1; i < data.size(); i++){
            data[i] += data[i - 1];
        }
    }
    //区間[0,k]の和
    int query(int k){
        if(k < 0) return 0;
        return (data[min(k, (int)data.size() - 1)]);
    }
    //区間[l.r)の和
    int query(int l, int r){
        return query(r - 1) - query(l - 1);
    }
};

int main(){
    int n, t;
    cin >> n >> t;
    CumulativeSum cs(t + 1);
    for(int i = 0; i < n; i++){
        int l, r;
        cin >> l >> r;
        cs.add(l, 1);
        cs.add(r, -1);
    }
    cs.build();
    int ans = 0;
    for(int i = 0; i <= t; i++){
        ans = max(ans, cs.query(i));
    }
    cout << ans << endl;
}

```