求助大佬救助！

#include<iostream>
using namespace std;
const long long maxx=1e7+5;
typedef unsigned long usl;
usl tree[maxx];
usl pd(usl h,usl n)
{
	usl sum=0;
	for(int i=0;i<n;i++)
	{
		if(tree[i]>h) sum+=tree[i]-h;
	}
	return sum;
}
int main()
{
	int n,m;
	cin>>n>>m;
	for(int i=0;i<n;i++) cin>>tree[i];
	usl l=1,r=1e9+5;
	usl ans;
	while(l<r)
	{
		usl mid=l+(r-l)/2;
		if(pd(mid,m)>=m)
		{
			ans=mid;
			l=mid+1;
		}
		else r=mid-1;
	}
	cout<<ans;
	return 0;
}