#include<iostream>

 #include<cstdio>

 #include<cstring>

 #include<algorithm>

 #include<vector>

 using namespace std;

 #define MAXN 100100

 typedef long long LL;

 #pragma comment(linker, "/STACK:1024000000,1024000000")

 struct Edge{

     int v,w;

     Edge(int vv,int ww):v(vv),w(ww){}

 };

 int n;

 int num[MAXN],sum;

 LL dp[MAXN],dist[MAXN],ans;

 vector<vector<Edge> >G;

 void dfs1(int u,int father)

 {

     for(int i=;i<G[u].size();i++){

         int v=G[u][i].v,w=G[u][i].w;

         if(v==father)continue;

         dist[v]=dist[u]+w;

         ans+=(LL)num[v]*dist[v];

         dfs1(v,u);

         num[u]+=num[v];

     }

 }

 void dfs2(int u,int father)

 {

     for(int i=;i<G[u].size();i++){

         int v=G[u][i].v,w=G[u][i].w;

         if(v==father)continue;

         dp[v]=dp[u]+(LL)(sum-num[v])*w-(LL)num[v]*w;

         dfs2(v,u);

     }

 }

 int main()

 {

     int u,v,w;

     while(~scanf("%d",&n)){

         G.clear();

         G.resize(n+);

         sum=;

         for(int i=;i<=n;i++){

             scanf("%d",&num[i]);

             sum+=num[i];

         }

         for(int i=;i<n;i++){

             scanf("%d%d%d",&u,&v,&w);

             G[u].push_back(Edge(v,w));

             G[v].push_back(Edge(u,w));

         }

         dist[]=;

         ans=;

         dfs1(,-);

         memset(dp,,sizeof(dp));

         dp[]=ans;

         dfs2(,-);

 //        cout<<ans<<"**"<<endl;

         for(int i=;i<=n;i++){

             ans=min(ans,dp[i]);

 //            cout<<dp[i]<<"***"<<endl;

         }

         printf("%I64d\n",ans);

     }

     return ;

 }