114514

#include<bits/stdc++.h>
#define ll long long
using namespace std;
vector<ll>g[114514];
ll val[114514],n,sum,d[114514],l,r,ans=1e9+1;
void dfs(ll u,ll f){
    for(ll v:g[u]){
        if(v!=f){
            d[v]=d[u]+1;
            dfs(v,u);
        }
    }
}
int main(){
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>val[i]>>l>>r;
        if(l)g[i].push_back(l);g[l].push_back(i);
        if(r)g[i].push_back(r);g[r].push_back(i);
    }
    for(int i=1;i<=n;i++){
        memset(d,0,sizeof(d));
        sum=0;
        dfs(i,0);
        for(int j=1;j<=n;j++)sum+=val[j]*d[j];
        ans=min(ans,sum);
    }
    cout<<ans;
    return 0;
}