#include <cstdio>
#define fin  "traseu.in"
#define fout "traseu.out"
#define Nmax 61

int N,M,g[Nmax][Nmax],viz[Nmax],c[Nmax];
int ret;

void df(int x,int cost) {
int y;
	c[x]=cost; viz[x]=1;
	for (y=1;y<=N;++y) 
	if (g[x][y]) 
		if (!viz[y])
			df(y,cost+g[x][y]);	
		else 
			ret=ret+cost-c[y]+g[x][y];		
}

int main() {
int i,j,x,y,k;
	freopen(fin,"r",stdin); freopen(fout,"w",stdout);

	scanf("%d%d",&N,&M);
	
	while ( M-- ) {
		scanf("%d%d%d",&x,&y,&k);
		g[x][y]=k;
	}

	df(1,0);
//printf("\n");
//	for (i=1;i<=N;++i)
//		printf("%d ",c[i]);

	printf("%d\n",ret);

	return 0;
}