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

struct C{
	int a,b,id;
};

bool cmp(const C&x,const C&y){
	if(x.a<=x.b&&y.a<=y.b)return x.a<y.a;
	if(x.a<=x.b)return 1;
	if(y.a<=y.b)return 0;
	return x.b>y.b;
}
int main(){
	freopen("service.in","r",stdin);
	freopen("service.out","w",stdout);
	int n;cin>>n;
	vector<C> c(n);
	for(int i=0;i<n;i++){cin>>c[i].a>>c[i].b;c[i].id=i+1;}
	sort(c.begin(),c.end(),cmp);
	long long t1=0,t2=0;
	for(int i=0;i<n;i++){t1+=c[i].a;t2=max(t2,t1)+c[i].b;}
	cout<<t2<<endl;
	return 0;
}