Description：

Solution：

Code：

#include<algorithm>

#include<iostream>

#include<cstdlib>

#include<cstdio>

#include<cmath>

#include<queue>

#include<cctype>

#include<cstring>

using namespace std;

int n,m;

#define MAXN 510

#define MAXM 100010

typedef long long ll;

struct dijkstra

{

	struct edge

	{

		int to,nxt;

		ll v;

	}e[MAXM << 1];

	int edgenum;

	int lin[MAXN];

	dijkstra(){edgenum = 0;memset(lin,0,sizeof(lin));}

	void add(int a,int b,ll c)

	{

		e[++edgenum] = (edge){b,lin[a],c};lin[a] = edgenum;

		e[++edgenum] = (edge){a,lin[b],c};lin[b] = edgenum;

		return;

	}

	ll d[MAXN];

	bool v[MAXN];

	int s;

	void dij()

	{

		priority_queue< pair<ll,int> > q;q.push(make_pair(0,s));

		memset(d,0x3f,sizeof(d));d[s] = 0;

		memset(v,false,sizeof(v));

		while(!q.empty())

		{

			int k = q.top().second;q.pop();

			if(v[k])continue;

			v[k] = true;

			for(int i = lin[k];i != 0;i = e[i].nxt)

			{

				if(d[e[i].to] > d[k] + e[i].v)

				{

					d[e[i].to] = d[k] + e[i].v;

					q.push(make_pair(-d[e[i].to],e[i].to));

				}

			}

		}

		return;

	}

}g,rg;

#define INF 0x3f3f3f3f3f3f3f3f

struct dinic

{

	struct edge

	{

		int to,nxt;

		ll f;

	}e[(MAXM + MAXN) << 1];

	int edgenum;

	int lin[MAXN << 1];

	dinic(){edgenum = 0;memset(lin,-1,sizeof(lin));}

	void add(int a,int b,ll f)

	{

		e[edgenum] = (edge){b,lin[a],f};lin[a] = edgenum++;

		e[edgenum] = (edge){a,lin[b],0};lin[b] = edgenum++;

		return;

	}

	int ch[MAXN << 1];

	int s,t;

	bool BFS()

	{

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

		memset(ch,-1,sizeof(ch));ch[s] = 0;

		while(!q.empty())

		{

			int k = q.front();q.pop();

			for(int i = lin[k];i != -1;i = e[i].nxt)

			{

				if(ch[e[i].to] == -1 && e[i].f)

				{

					ch[e[i].to] = ch[k] + 1;

					q.push(e[i].to);

				}

			}

		}

		return (ch[t] != -1);

	}

	ll flow(int k,int f)

	{

		if(k == t)return f;

		ll r = 0;

		for(int i = lin[k];i != -1 && f > r;i = e[i].nxt)

		{

			if(ch[e[i].to] == ch[k] + 1 && e[i].f)

			{

				ll l = flow(e[i].to,min(e[i].f,f - r));

				e[i].f -= l;r += l;e[i ^ 1].f += l;

			}

		}

		if(r == 0)ch[k] = -1;

		return r;

	}

	ll mf()

	{

		ll ans = 0,r;

		while(BFS())while(r = flow(s,INF))ans += r;

		return ans;

	}

}s;

int main()

{

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

	int a,b,c;

	for(int i = 1;i <= m;++i)

	{

		scanf("%d%d%d",&a,&b,&c);

		g.add(a,b,(ll)c);

		rg.add(b,a,(ll)c);

	}

	g.s = 1;g.dij();

	rg.s = n;rg.dij();

	s.s = 3;s.t = n << 1;

	for(int k = 1;k <= n;++k)

	{

		int x;

		scanf("%d",&x);

		s.add(k << 1,k << 1 | 1,(ll)x);

		for(int i = g.lin[k];i != 0;i = g.e[i].nxt)

		{

			if(g.d[k] + g.e[i].v + rg.d[g.e[i].to] == g.d[n])

			{

				s.add(k << 1 | 1,g.e[i].to << 1,INF);

			}

		}

	}

	cout << s.mf() << endl;

	return 0;

}