import std.stdio, std.array, std.string, std.conv, std.algorithm;
import std.typecons, std.range, std.random, std.math, std.container;
import std.numeric, std.bigint, core.bitop, core.stdc.stdlib;

void main() {
    auto s = readln.split.map!(to!int);
    auto N = s[0];
    auto M = s[1];
    auto G = new int[][](N);
    foreach (i; 0..M) {
        s = readln.split.map!(to!int);
        auto u = s[0] - 1;
        auto v = s[1] - 1;
        auto c = s[2];
        G[u] ~= v;
        if (c == 1) G[v] ~= u;
    }

    auto visited = new bool[](N);

    bool dfs(int n, int p) {
        if (visited[n]) return true;
        visited[n] = true;
        foreach (m; G[n]) {
            if (p == m) continue;
            if (dfs(m, n)) return true;
        }
        return false;
    }

    writeln(dfs(0, -1) ? "Yes" : "No");
}