#include<bits/stdc++.h>
using namespace std;
int n,ta[3005],tb[3005],ans=INT_MAX;
void dfs(int cs,int sum1,int sum2){
    if (cs==n+1){
        ans=min(ans,max(sum1,sum2));
        return;
    }
    for (int i=1;i<=2;i++){
        if (i==1){
            dfs(cs+1,sum1+ta[cs],sum2);
        }else{
            dfs(cs+1,sum1,sum2+tb[cs]);
        }
    }
}
int main(){
    freopen("task.in","r",stdin);
    freopen("task.out","w",stdout);
    scanf("%d",&n);
    for (int i=1;i<=n;i++){
        scanf("%d%d",&ta[i],&tb[i]);
    }
    dfs(1,0,0);
    printf("%d",ans);
    
    
    /*fa[1]=ta[1],fb[1]=tb[1];
    for (int i=2;i<=n;i++){
        fa[i][0]=min(fa[i-1][0]+ta[i],fa[i-1][1]+ta[i]);
        fa[i][1]=min(min(fa[i-1][0]+ta[i],fa[i-1][1]+ta[i]),min(max(ta[i],fb[i-1][0]),INT_MAX));
        fb[i][0]=min(fb[i-1][0]+tb[i],fb[i-1][1]+tb[i]);
        fb[i][1]=min(min(fb[i-1][0]+tb[i],fb[i-1][1]+tb[i]),min(max(tb[i],fa[i-1][0]),INT_MAX));
        //fa[i]=min(fa[i-1]+ta[i],max(fb[i-1],ta[i]+fa[i-2]));//max(ta[i]+fa[i-2][0],fb[i-1][1])
        //fb[i]=min(fb[i-1]+tb[i],max(fa[i-1],tb[i]+fb[i-2]));//max(tb[i]+fb[i-2][0],fa[i-1][1])
    }
    int ans=min(fa[n],fb[n]);*/
    return 0;
}