#include <iostream>
#include <cstdio>
#include <algorithm>
#include <string.h>
#include <vector>
#include <queue>
using namespace std;
const int maxn = 1000+10;
const int INF = 1000000000;
struct Edge{int from,to,dist;
};
struct HeapNode{int d,u;bool operator <(const HeapNode &rhs)const {return d>rhs.d;}
};
struct Dijkstra{int n,m;vector<Edge> edges;vector<int>G[maxn];bool done[maxn];int d[maxn];int p[maxn];void inti(int n){this->n=n;for(int i=0; i < n; ++i)G[i].clear();edges.clear();}void AddEdge(int from, int to, int dist){edges.push_back((Edge){from,to,dist});int m =edges.size();G[from].push_back(m-1);}void dijkstra(int s){priority_queue<HeapNode> Q;for(int i=0; i<n; i++) d[i]=INF;d[s] = 0;memset(done, false,sizeof(done));Q.push((HeapNode){0,s});while(!Q.empty()){HeapNode x =Q.top();Q.pop();int u =x.u;if(done[u])continue;done[u] =true;for(int i=0; i<G[u].size(); ++i){Edge &e = edges[G[u][i]];if(d[e.to]>d[u]+e.dist){d[e.to] = d[u] +e.dist;p[e.to]  = G[u][i];Q.push((HeapNode){d[e.to],e.to});}}}}
}solve1;
vector<int> R[maxn];
int dp[maxn];
int dfs(int u){if(dp[u]!=-1)  return dp[u];if(u==1) return 1;dp[u]=0;for(int i =0 ; i<R[u].size(); i++){int v = R[u][i];dp[u]+=dfs(v);}return dp[u];
}
int main()
{int n,m;while(scanf("%d",&n)==1&&n){scanf("%d",&m);solve1.inti(n);for(int i = 0; i<m; ++i){int u,v,d;scanf("%d%d%d",&u,&v,&d); u--,v--;solve1.AddEdge(u,v,d);solve1.AddEdge(v,u,d);}solve1.dijkstra(1);for(int i = 0; i<n; i++) R[i].clear();for(int i = 0; i < solve1.edges.size(); ++i){int u=solve1.edges[i].from, v=solve1.edges[i].to;if(solve1.d[u]>solve1.d[v])R[u].push_back(v);}memset(dp,-1,sizeof(dp));printf("%d\n",dfs(0));}return 0;
}