#include<bits/stdc++.h>
using namespace std;
int n,peo_wait,ans;
struct node{
	int d,u;
}cow[25001];
inline int cmp(node x,node y){return x.u<y.u;}
int main(){
	scanf("%d",&n);
	for(register int i=1;i<=n;i++){
		scanf("%d%d",&cow[i].u,&cow[i].d);
	}
	sort(cow+1,cow+n+1,cmp);
	for(register int i=1;i<=n;i++){
		peo_wait+=cow[i].u;
		ans+=cow[i].d;
	}
	if(peo_wait>=ans-cow[n].d)peo_wait-=(ans-cow[n].d);
	else peo_wait=cow[1].u;
	printf("%d\n",ans+peo_wait);
	return 0;
}