#include <bits/stdc++.h>  
using namespace std;  

#define int long long  

signed main() {  
    ios::sync_with_stdio(false);
    cin.tie(nullptr);  

	int n, m;
	cin >> n >> m;

	vector<vector<pair<int, int>>> adj(n + 1);
	vector<int> f(n + 1);
	while (m--) {
		int x, y, z;
		cin >> x >> y >> z;
		int t = adj.size();
		adj.emplace_back();
		f.emplace_back();
		adj[y].emplace_back(t, 0);
		adj[z].emplace_back(t, 0);
		adj[t].emplace_back(x, 1);	
		f[t] += 2, f[x]++;
	}

	queue<int> q;
	vector<int> ans(f.size());
	for (int i = 1; i <= n; i++) {
		if (f[i] == 0) {
			q.push(i);
			ans[i] = 1;
		}
	}
	while (!q.empty()) {
		int x = q.front();
		q.pop();

		for (auto [y, tp] : adj[x]) {
			if (tp == 0) {
				ans[y] += ans[x];
			} else {
				ans[y] = max(ans[y], ans[x]);
			}
			f[y]--;
			if (f[y] == 0) {
				q.push(y);
			}
		}
	}

	int s = 0;
	for (int i = 1; i <= n; i++) {
		s += ans[i];
	}

	cout << s << "\n";

    return 0;	
}