#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=100000+5;
const ll inf=0x3f3f3f3f3f3f;
struct sdf{
    int to,next;
}eg[N];
int head[N],ne;
int n,in[N];
ll w[N],ans=0,mn=inf;
queue<int>q;
void add(int x,int y){
    eg[++ne]={y,head[x]};
    head[x]=ne;return ;
}
bool vis[N]={0};
void dfs(int pt){
    vis[pt]=1;mn=min(mn,w[pt]);
    for (int i=head[pt];i!=0;i=eg[i].next){
        int v=eg[i].to;
        if (!in[v]||vis[v])continue;
        dfs(v);
    }
    return ;
}
int main(){
	freopen ("prob1_silver_22open.in","r",stdin);
	freopen ("prob1_silver_22open.out","w",stdout);
	scanf("%d",&n);
	for (int i=1;i<=n;i++){
	    int x;scanf("%d%lld",&x,&w[i]);
	    add(i,x);in[x]++;ans+=w[i];
    }
    for (int i=1;i<=n;i++){
        if (!in[i])q.push(i);
    }
    while(!q.empty()){
        int pt=q.front();q.pop();
        for (int i=head[pt];i!=0;i=eg[i].next){
            int v=eg[i].to;
            if (!in[v])continue;
            in[v]--;
            if (!in[v])q.push(v);
        }
    }
    for (int i=1;i<=n;i++){
        if (in[i]&&!vis[i])mn=inf,dfs(i),ans-=mn;
    }
    printf("%lld\n",ans);
    return 0;
}