import java.util.*;

public class Main {
    static ArrayList<ArrayList<Integer>> graph = new ArrayList<>();
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        for (int i = 0; i < n; i++) {
            graph.add(new ArrayList<>());
        }
        for (int i = 0; i < m; i++) {
            int a = sc.nextInt() - 1;
            int b = sc.nextInt() - 1;
            int c = sc.nextInt();
            graph.get(a).add(b);
            if (c == 1) {
                graph.get(b).add(a);
            }
        }
        for (int i = 0; i < n; i++) {
            search(i, -1, new boolean[n]);
        }
        System.out.println("No");
    }
    
    static void search(int idx, int from, boolean[] visited) {
        if (visited[idx]) {
            System.out.println("Yes");
            System.exit(0);
        }
        visited[idx] = true;
        boolean flag = true;
        for (int x : graph.get(idx)) {
            if (x == from && flag) {
                flag = false;
               continue;
             }
            search(x, idx, visited);
        }
        visited[idx] = false;
    }
}