两个点 RE 呢，是不是程序炸了？

#include<bits/stdc++.h>
#define int long long
using namespace std;
const int MAXN=1e5+10;
int n;
int ans[MAXN];
int sum;
int cnt;
signed main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin>>n;
	if (n==0)
	{
		cout<<0;
		return 0;
	}
	for (int i=1;i<=n;++i)
	{
		int a,b;
		cin>>a>>b;
		ans[a+1]++;
		ans[b+2]--;
	}
	for (int i=1;i<=MAXN-9;++i)
	{
		cnt+=ans[i];
		sum=max(sum,cnt);
	}
	cout<<sum;
	return 0;
}