#include<bits/stdc++.h>
using namespace std;
template<typename T>inline void read(T &x){
	x=0;
	bool flag=0;
	char ch=getchar();
	while(ch<'0'||ch>'9') flag=flag||(ch=='-'),ch=getchar();
	while(ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar();
	x=flag?-x:x;
}
template<typename T,typename ...Args>inline void read(T &x,Args &...args){
	read(x),read(args...);
}
template<typename T>inline void prt(T x){
	if(x>9) prt(x/10);
	putchar(x%10+'0');
}
template<typename T>inline void put(T x){
	if(x<0) putchar('-'),x=-x;
	prt(x);
}
template<typename T>inline void put(char ch,T x){
	put(x),putchar(ch);
}
template<typename T,typename ...Args>inline void put(char ch,T x,Args ...args){
	put(ch,x),put(ch,args...);
}
#define N 2024
struct Flow{
	int head[N],cnt,s,t;
	Flow(){
		memset(head,0,sizeof(head));
		memset(e,0,sizeof(e));
		cnt=1;
	}
	struct edge{
		int v,nxt,flow,cost;
	}e[N<<2];
	inline void adde(int u,int v,int flow,int cost){
		e[++cnt]=(edge){v,head[u],flow,cost},head[u]=cnt;
	}
	inline void add(int u,int v,int flow,int cost){
		adde(u,v,flow,cost),adde(v,u,0,-cost);
	}
	int dis[N],vis[N],incf[N],pre[N];
	inline bool spfa(){
		memset(dis,0x3f,sizeof(dis));
		memset(vis,0,sizeof(vis));
		queue<int> q;
		q.push(s),dis[s]=0,vis[s]=1,incf[s]=0x3f3f3f3f;
		while(!q.empty()){
			int x=q.front();q.pop(),vis[x]=0;
			for(int i=head[x];i;i=e[i].nxt){
				int v=e[i].v;
				if(e[i].flow&&dis[v]>dis[x]+e[i].cost){
					dis[v]=dis[x]+e[i].cost,incf[v]=min(incf[x],e[i].flow),pre[v]=i;
					if(!vis[v]) vis[v]=1,q.push(v);
				}
			}
		}
		return dis[t]<0x3f3f3f3f;
	}
	inline int mcmf(){
		int res=0;
		while(spfa()){
			res+=dis[t]*incf[t];
			for(int x=t,i=pre[x];x!=s;x=e[i^1].v,i=pre[x])
				e[i].flow-=incf[t],e[i^1].flow+=incf[t];
		}
		return res;
	}
}F;
int n,m,deg[N],ans;
int main(){
	read(n,m);
	for(int i=1,u,v,w;i<=n;i++){
		read(u,v,w),F.add(v,u,w,1),ans+=w;
		deg[u]+=w,deg[v]-=w;
	}
	F.s=0,F.t=n+1;
	for(int i=1;i<=n;i++)
		if(deg[i]>0) F.add(F.s,i,deg[i],0);
		else if(deg[i]<0) F.add(i,F.t,-deg[i],0);
	put('\n',ans-F.mcmf());
	return 0;
}