#include<cstdio>

 #include<cstdlib>

 #include<cstring>

 #include<iostream>

 #include<algorithm>

 #include<queue>

 using namespace std;

 #define Maxn 1010

 struct node

 {

     int x,y,c,next;

 }t[*Maxn*Maxn];int len;

 int n,m;

 int first[Maxn],dis[Maxn],f[Maxn];

 bool inq[Maxn];

 void ins(int x,int y,int c)

 {

     t[++len].x=x;t[len].y=y;t[len].c=c;

     t[len].next=first[x];first[x]=len;

 }

 void spfa(int s)

 {

     queue<int >     q;

     while(!q.empty()) q.pop();

     q.push(s);

     memset(dis,,sizeof(dis));

     memset(inq,,sizeof(inq));

     dis[s]=;

     while(!q.empty())

     {

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

         for(int i=first[x];i;i=t[i].next)

         {

             int y=t[i].y;

             if(dis[y]>dis[x]+t[i].c)

             {

                 dis[y]=dis[x]+t[i].c;

                 if(!inq[y]) {inq[y]=;q.push(y);}

             }

         }

         inq[x]=;

     }

 }

 int ffind(int x)

 {

     if(f[x]!=-) return f[x];

     f[x]=;

     for(int i=first[x];i;i=t[i].next) if(dis[x]>dis[t[i].y])

     {

         f[x]+=ffind(t[i].y);

     }

     return f[x];

 }

 int main()

 {

     while()

     {

         scanf("%d",&n);

         if(n==) break;

         scanf("%d",&m);

         len=;

         memset(first,,sizeof(first));

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

         {

             int x,y,c;

             scanf("%d%d%d",&x,&y,&c);

             ins(x,y,c);ins(y,x,c);

         }

          spfa();

          memset(f,-,sizeof(f));

          f[]=;

          ffind();

          printf("%d\n",f[]);

     }

     return ;

 }