#include<bits/stdc++.h>
using namespace std;
int n,num;
struct pp
{
	int w,v;
}a[50005];
void dfs(int x,int y)
{
	if(x==n+1)
	{
		return;
	}
	num+=a[x].w-y;
	y+=a[x].v;
	if(a[x+1].w<=y)
	{
		return;
	}
	dfs(x+1,y);
}
int cmp(pp x,pp y)
{
	if(x.v!=y.v)
	{
		return x.v<y.v;
	}
	else
	{
		return x.w>=y.w;
	}
}
int main()
{
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i].w>>a[i].v;
	}
	sort(a+1,a+n+1,cmp);
	dfs(1,0);
	cout<<num;
}

这只能过2个点 麻烦各位大佬捏个数据