#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <queue>
#include <vector>
#define min(a,b)    (((a) < (b)) ? (a) : (b))
#define max(a,b)    (((a) > (b)) ? (a) : (b))
#define abs(x)    ((x) < 0 ? -(x) : (x))
#define INF 0x3f3f3f3f
#define delta 0.85
#define eps 1e-10
#define PI 3.14159265358979323846
using namespace std;

#define MAX_V 102
struct edge{
	int to, cap, cost, rev;
	edge(int to, int cap, int cost, int rev):to(to), cap(cap), cost(cost), rev(rev){}
};

int V;
vector<edge> G[MAX_V];
int h[MAX_V], dist[MAX_V];
int prevv[MAX_V], preve[MAX_V];
bool inq[MAX_V];

void add_edge(int from, int to, int cap, int cost){
	G[from].push_back(edge(to, cap, cost, G[to].size()));
	G[to].push_back(edge(from, 0, -cost, G[from].size() - 1));
}

int min_cost_flow(int s, int t, int f){
	int res = 0;
	memset(h, 0, sizeof(h));
	// Spfa
	memset(inq, 0, sizeof(inq));
	memset(dist, 0x3f, sizeof(dist));
	queue<int> q;
	dist[s] = 0;
	q.push(s);
	inq[s] = 1;
	while(!q.empty()){
		int v = q.front(); q.pop();
		inq[v] = 0;
		for(int i = 0; i < G[v].size(); i++){
			edge &e = G[v][i];
			int d2 = dist[v] + e.cost;
			if(e.cap > 0 && dist[e.to] > d2){
				dist[e.to] = d2;
				if(!inq[e.to]){
					q.push(e.to);
					inq[e.to] = 1;
				}
			}
		}
	}
	for(int v = 0; v < V; v++) h[v] = dist[v];
	
	while(f > 0){
		// Dijkstra
		priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > > que;
		memset(dist, 0x3f, sizeof(dist));
		dist[s] = 0;
		que.push(pair<int, int>(0, s));
		while(!que.empty()){
			pair<int, int> p = que.top(); que.pop();
			int v = p.second;
			if(dist[v] < p.first) continue;
			for(int i = 0; i < G[v].size(); i++){
				edge &e = G[v][i];
				int d2 = dist[v] + e.cost + h[v] - h[e.to];
				if(e.cap > 0 && d2 < dist[e.to]){
					dist[e.to] = d2;
					prevv[e.to] = v;
					preve[e.to] = i;
					que.push(pair<int, int>(dist[e.to], e.to));
				}
			}
		}
		if(dist[t] == INF){
			return -1;
		}
		for(int v = 0; v < V; v++) h[v] += dist[v];
		int d = f;
		for(int v = t; v != s; v = prevv[v]){
			d = min(d, G[prevv[v]][preve[v]].cap);
		}
		f -= d;
		res += d * h[t];
		for(int v = t; v != s; v = prevv[v]){
			edge &e = G[prevv[v]][preve[v]];
			e.cap -= d;
			G[v][e.rev].cap += d;
		}
	}
	return res;
}

void clear_graph(){
	for(int v = 0; v < V; v++) G[v].clear();
}

int spfa(int s, int t){
	memset(inq, 0, sizeof(inq));
	memset(dist, 0x3f, sizeof(dist));
	queue<int> q;
	dist[s] = 0;
	q.push(s);
	inq[s] = 1;
	while(!q.empty()){
		int v = q.front(); q.pop();
		inq[v] = 0;
		for(int i = 0; i < G[v].size(); i++){
			edge &e = G[v][i];
			int d2 = dist[v] + e.cost;
			if(e.cap > 0 && dist[e.to] > d2){
				dist[e.to] = d2;
				if(!inq[e.to]){
					q.push(e.to);
					inq[e.to] = 1;
				}
			}
		}
	}
	return dist[t];
}

#define MAX_N 100
#define MAX_M 1000
int N, M;
int X[MAX_M], Y[MAX_M], S[MAX_M];
int deg[MAX_N]; // deg[i] > 0, in_degree > out_degree

void solve(){
	int s = N, t = s + 1;
	V = t + 1;
	clear_graph();
	
	int res = 0, f = 0;
	memset(deg, 0, sizeof(deg));
	for(int i = 0; i < M; i++){
		deg[X[i]]--, deg[Y[i]]++;
		add_edge(X[i], Y[i], INF, -S[i]);
		res -= S[i];
	}
	for(int i = 0; i < N; i++){
		if(deg[i] > 0){
			add_edge(s, i, deg[i], 0);
			f += deg[i];
		}
		if(deg[i] < 0){
			add_edge(i, t, -deg[i], 0);
		}
	}
	add_edge(N - 1, 0, INF, -spfa(0, N - 1));
	
	res += min_cost_flow(s, t, f);
	printf("%d\n", res);
}

int main(){
	while(~scanf("%d%d", &N, &M)){
		for(int i = 0; i < M; i++){
			scanf("%d%d%d", X + i, Y + i, S + i);
		}
		solve();
	}
	return 0;
}



Measured memory_bytes: 3292