#include <algorithm>

#include  <iterator>

#include  <iostream>

#include   <cstring>

#include   <cstdlib>

#include   <iomanip>

#include    <bitset>

#include    <cctype>

#include    <cstdio>

#include    <string>

#include    <vector>

#include     <stack>

#include     <cmath>

#include     <queue>

#include      <list>

#include       <map>

#include       <set>

#include   <cassert>

using namespace std;

#define lson (l , mid , rt << 1)

#define rson (mid + 1 , r , rt << 1 | 1)

#define debug(x) cerr << #x << " = " << x << "\n";

#define pb push_back

#define pq priority_queue

typedef long long ll;

typedef unsigned long long ull;

//typedef __int128 bll;

typedef pair<ll ,ll > pll;

typedef pair<int ,int > pii;

typedef pair<int,pii> p3;

//priority_queue<int> q;//这是一个大根堆q

//priority_queue<int,vector<int>,greater<int> >q;//这是一个小根堆q

#define fi first

#define se second

//#define endl '\n'

#define OKC ios::sync_with_stdio(false);cin.tie(0)

#define FT(A,B,C) for(int A=B;A <= C;++A)  //用来压行

#define REP(i , j , k)  for(int i = j ; i <  k ; ++i)

#define max3(a,b,c) max(max(a,b), c);

#define min3(a,b,c) min(min(a,b), c);

//priority_queue<int ,vector<int>, greater<int> >que;

const ll oo = 1ll<<;

const ll mos = 0x7FFFFFFF;  //

const ll nmos = 0x80000000;  //-2147483648

const int inf = 0x3f3f3f3f;

const ll inff = 0x3f3f3f3f3f3f3f3f; //

const int mod = ;

const double esp = 1e-;

const double PI=acos(-1.0);

const double PHI=0.61803399;    //黄金分割点

const double tPHI=0.38196601;

template<typename T>

inline T read(T&x){

    x=;int f=;char ch=getchar();

    while (ch<''||ch>'') f|=(ch=='-'),ch=getchar();

    while (ch>=''&&ch<='') x=x*+ch-'',ch=getchar();

    return x=f?-x:x;

}

/*-----------------------showtime----------------------*/

            const int maxn = 1e5+;

            vector<pii>mp[maxn*];

            int a[maxn];

            int n,m;

            void addedge(int s,int t){

                mp[s].pb(pii(t, ));

                mp[s + n].pb(pii(t + n,));

                mp[s +  * n].pb(pii(t +  * n,));

                mp[s].pb(pii(t + n, -a[s]));

                mp[s + n].pb(pii(t +  * n, a[s]));

            }

            int dis[maxn * ];

            bool vis[maxn * ];

            int spfa(int s,int t){

                memset(dis, -inf,sizeof(dis));

                dis[s] = ;

                queue<int>que;  que.push(s);

                vis[s] = true;

                while(!que.empty()){

                    int u = que.front(); que.pop();

                    vis[u] = false;

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

                        int v = mp[u][i].fi,w = mp[u][i].se;

                        if(dis[v] < dis[u] + w){

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

                            if(vis[v] == false){

                                vis[v] = true;

                                que.push(v);

                            }

                        }

                    }

                }

                return dis[t];

            }

int main(){

            scanf("%d%d", &n, &m);

            int t =  * n + ;

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

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

                int u,v,c;

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

                if(c == ) {

                    addedge(u,v);

                }

                else {

                    addedge(u,v);

                    addedge(v,u);

                }

            }

            // addedge(3*n, t);

            mp[*n].pb(pii(t,));

            mp[n].pb(pii(t, ));

            printf("%d\n", spfa(, t));

            return ;

}