#include <set>
#include <map>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <string>
#include <vector>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>using namespace std;typedef long long ll;
typedef unsigned long long ull;#define debug puts("here")
#define rep(i,n) for(int i=0;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define REP(i,a,b) for(int i=a;i<=b;i++)
#define foreach(i,vec) for(unsigned i=0;i<vec.size();i++)
#define pb push_back
#define RD(n) scanf("%d",&n)
#define RD2(x,y) scanf("%d%d",&x,&y)
#define RD3(x,y,z) scanf("%d%d%d",&x,&y,&z)
#define RD4(x,y,z,w) scanf("%d%d%d%d",&x,&y,&z,&w)
#define All(vec) vec.begin(),vec.end()
#define MP make_pair
#define PII pair<int,int>
#define PQ priority_queue
#define cmax(x,y) x = max(x,y)
#define cmin(x,y) x = min(x,y)
#define Clear(x) memset(x,0,sizeof(x))
/*#pragma comment(linker, "/STACK:1024000000,1024000000")int size = 256 << 20; // 256MB
char *p = (char*)malloc(size) + size;
__asm__("movl %0, %%esp\n" :: "r"(p) );*//******** program ********************/const int MAXN = 1e5+5;
const ll INF = 1e15;struct Edge{int y,cost,next;
}edge[MAXN<<1];int c[MAXN],n;
ll dp[MAXN],sz[MAXN],ans[MAXN];
int po[MAXN],tol;inline void add(int x,int y,int cost){edge[++tol].y = y;edge[tol].cost = cost;edge[tol].next = po[x];po[x] = tol;
}void dfsDp(int x,int fa){dp[x] = 0;sz[x] = c[x];for(int i=po[x];i;i=edge[i].next){int y = edge[i].y;if(y==fa)continue;dfsDp(y,x);sz[x] += sz[y];dp[x] += sz[y]*edge[i].cost+dp[y];}
}void dfsAns(int x,int fa,ll cost){ans[x] = cost;for(int i=po[x];i;i=edge[i].next){int y = edge[i].y;if(y==fa)continue;ll tmp = cost+(sz[1]-2*sz[y])*edge[i].cost;dfsAns(y,x,tmp);}
}int main(){#ifndef ONLINE_JUDGEfreopen("sum.in","r",stdin);//freopen("sum.out","w",stdout);
#endifwhile(~RD(n)){rep1(i,n)RD(c[i]);int x,y,cost;REP(i,2,n){RD3(x,y,cost);add(x,y,cost);add(y,x,cost);}dfsDp(1,0);dfsAns(1,0,dp[1]);ll tmp = INF;rep1(i,n)cmin(tmp,ans[i]);cout<<tmp<<endl;}return 0;
}