#include<stdio.h>
int n,m;
int ship[3001][3001]={0},count[3001]={0};
int i,j;
int a,b,c;
int main(){
while(scanf("%d%d",&n,&m)!=EOF){
for(i=1;i<=m;i++){
scanf("%d%d%d",&a,&b,&c);
ship[a][b]=c;
ship[b][a]=c;
}
int min_ship=0;
for(i=1;i<=n;i++){
for(j=1;j<=n;j++){
if(ship[i][j]!=0){
count[i]+=ship[i][j];
}
if(j==n&&count[i]<min_ship){
min_ship=count[i];
}
}
if(i==1){
min_ship=count[1];
}
}
printf("%d",min_ship);
}
return 0;
}
