#include<bits/stdc++.h>
using namespace std;
int l[25005],r[25005];
int main()
{
	int n;
	int t;
	scanf("%d %d",&n,&t); 
	for(int i = 1;i<=n;i++)
	{
		scanf("%d %d",&l[i],&r[i]);
	}
	int num = 0;
	int x = 1;
	while(1)
    {
        int maxxx;
        int maxx = INT_MIN;
        for(int i = 1;i<=n;i++)
        {
            if(maxx<r[i]&&l[i]<=x)
            {
                maxx = r[i];
                maxxx = i;
            }
        }
        num++;
        x = maxx+1;
        if(maxx == t)
        {
            break;
        }
    }
    printf("%d",num);
	return 0;
} 

TLE63，怎么改