#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;

#define N 20005
int n,m;
int dad[N];

int find(int a) {
	if (dad[a]==a) return a;
	else return dad[a]=find(dad[a]);
}
void unify(int a, int b) {
	dad[find(a)]=find(b);
}

int main() {
	while(scanf("%d%d",&n,&m)==2&&n|m) {
		for (int i=0;i<n;++i) dad[i]=i;
		vector<pair<int,pair<int,int> > > tsd;
		for (int i=0;i<m;++i) {
			int t,s,d; scanf("%d%d%d",&t,&s,&d); --s,--d;
			tsd.push_back(make_pair(t,make_pair(s,d)));
		}
		sort(tsd.begin(),tsd.end());
		for (size_t i=0;i<tsd.size();++i)
			if (find(tsd[i].second.first)==find(0))
				unify(tsd[i].second.first,tsd[i].second.second);
		int ans=0;
		for (int i=0;i<n;++i)
			if (find(i)==find(0))
				++ans;
		printf("%d\n",ans);
	}
}