#include<bits/stdc++.h>
#define N 100005
using namespace std;
int n;
struct node{
    int a,b,c;
}x[55];
bool cmp(node a,node b){
    return a.c<b.c;
}
int pre[55],suf[55];
int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    cin>>n;
    for(int i=1;i<=n;++i){
        cin>>x[i].a>>x[i].b;
        x[i].c=x[i].a-x[i].b;
    }
    sort(x+1,x+1+n,cmp);
    for(int i=1;i<=n;++i)
        pre[i]=pre[i-1]+x[i].a;
    for(int i=n;i>=1;--i)
        suf[i]=suf[i+1]+x[i].b;
    int ans=pre[n];
    for(int i=0;i<=n;++i)
        ans=min(ans,max(pre[i],suf[i+1]));
    cout<<ans<<'\n';
    return 0;
}