#pragma comment(linker, "/STACK:16777216") //for c++ Compiler

#include <stdio.h>

#include <iostream>

#include <cstring>

#include <cmath>

#include <stack>

#include <queue>

#include <vector>

#include <algorithm>

#define ll long long

#define Max(a,b) (((a) > (b)) ? (a) : (b))

#define Min(a,b) (((a) < (b)) ? (a) : (b))

#define Abs(x) (((x) > 0) ? (x) : (-(x)))

using namespace std;

const int INF = 0x3f3f3f3f;

const int MAXN = ;

struct edge{

    int v, w;

    edge(){}

    edge(int a, int b) : v(a), w(b){}

};

vector <edge> node[MAXN];

int n,sum[MAXN],a[MAXN];

//a[MAXN]表示每一个节点的权值，sum[MAXN]表示子树的权值和

ll dist[MAXN];

bool vis[MAXN];

void init(){

    for(ll i = ; i <= n; ++i)

        node[i].clear();

    memset(vis, , sizeof(vis));

    memset(dist,,sizeof(dist));

}

void dfs(ll u,ll dis){

    vis[u] = true;

    dist[] += dis * a[u];

    sum[u] = a[u];

    ll size = node[u].size();

    for(ll i = ; i < size; ++i){

        ll v = node[u][i].v;

        if(vis[v]) continue;

        dfs(v, dis + node[u][i].w);

        sum[u] += sum[v];

    }

}

void dfs1(ll u){

    vis[u] = true;

    ll size = node[u].size();

    for(ll i = ; i < size; ++i){

        ll v = node[u][i].v;

        ll w = node[u][i].w;

        if(vis[v]) continue;

        dist[v] = dist[u] - sum[v] * w + (sum[] - sum[v]) * w;

        //dist[v] = dist[u] + (sum[1] - 2 * sum[v]) * w;

        dfs1(v);

    }

}

int main(){

    ll i, j, x, y, w;

    while(EOF != scanf("%I64d",&n)){

        init();

        for(i = ; i <= n; ++i)   scanf("%I64d",&a[i]);

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

            scanf("%I64d %I64d %I64d",&x,&y,&w);

            node[x].push_back(edge(y,w));

            node[y].push_back(edge(x,w));

        }

        dfs(,);

        memset(vis,,sizeof(vis));

        dfs1();

        ll ans = dist[];

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

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

        }

        cout << ans << endl;

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

    }

    return ;

}