#include<bits/stdc++.h>
using namespace std;
const int maxn=110;
struct node{
	int fa,left,right,w;
}e[maxn*2];
int n;
int cnt[maxn];
bool vis[maxn];
void dfs(int x,int step){
	cnt[x]=step;
	vis[x]=true;
	if(vis[e[x].left]!=true&&e[x].left!=0) dfs(e[x].left,step+1);
	if(vis[e[x].right]!=true&&e[x].right!=0) dfs(e[x].right,step+1);
	if(vis[e[x].fa!=true&&e[x].fa!=0]) dfs(e[x].fa,step+1);
}
int main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>e[i].w>>e[i].left>>e[i].right;
		e[e[i].left].fa=i;
		e[e[i].right].fa=i;
	}
	int ans=0x7f7f7f7f;
	for(int i=1;i<=n;i++){
		memset(cnt,0,sizeof(cnt));
		dfs(i,0);
		int sum=0;
		for(int j=1;j<=n;j++){
			sum+=e[i].w*cnt[i];
			//cout<<sum<<" ";
		}
		//cout<<endl;
		ans=min(ans,sum);
	}
	cout<<ans;
	return 0;
}