#include <stdio.h>
#include <iostream>
#include <string.h>
#include <algorithm>
#include <math.h>
using namespace std;
const int N = 1005;
const int INF = 99999999;
int graph[N][N];
int n,m;
bool vis[N];
int low[N];
int dp[N];
void dijkstra(int n,int pos)
{
    memset(vis,0,sizeof(vis));
    vis[pos]=1;
    for(int i=1; i<=n; i++) low[i]=graph[pos][i];
    low[pos] = 0;
    for(int i=1; i<n; i++)
    {
        int Min=INF;
        for(int j=1; j<=n; j++)
            if(vis[j]==0&&Min>low[j])
            {
                pos=j;
                Min=low[j];
            }
        vis[pos]=1;
        for(int j=1; j<=n; j++)
            if(vis[j]==0&&low[j]>graph[pos][j]+low[pos])
            {
                low[j]=graph[pos][j]+low[pos];
            }
    }
}
int dfs(int s,int n){
    if(dp[s]>0) return dp[s];
    int ans = 0;
    for(int i=1;i<=n;i++){
        if(graph[s][i]<INF&&low[s]>low[i]&&i!=s){
            ans+=dfs(i,n);
        }
    }
    dp[s] = ans;
    return dp[s];
}
int main()
{
    while(scanf("%d",&n)!=EOF,n)
    {
        scanf("%d",&m);
        for(int i=1;i<=n;i++){
            for(int j=1;j<=n;j++) graph[i][j]=INF;
        }
        for(int i=1; i<=m; i++)
        {
            int a,b,c;
            scanf("%d%d%d",&a,&b,&c);
            graph[a][b]=graph[b][a] = c;
        }
        dijkstra(n,2);
        memset(dp,0,sizeof(dp));
        dp[2]=1;
        printf("%d\n",dfs(1,n));
    }
}