#include <stdio.h>
#include <string>
#include <cstring>
#include <stdlib.h>
#include <math.h>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <list>
#include <iterator>
#include <assert.h>
#pragma warning(disable:4996) 

typedef long long ll;
#define MIN(a, b) ((a)>(b)? (b): (a))
#define MAX(a, b) ((a)<(b)? (b): (a))
#define LINF 9223300000000000000
#define INF 2140000000
const long long MOD = 1000000007;
//const long long MOD = 998244353;

using namespace std;

vector<vector<pair<int,int> > > g;     // to, directed edge
vector<int> vis,fin;

bool dfs(int paredge, int curr)
{
    assert(vis[curr]==0);
    vis[curr]=1;
    int i;
    for(i=0; i<(int)g[curr].size(); i++) {
        int next=g[curr][i].first;
        int edge=g[curr][i].second;
        if(paredge==edge) continue;
        if(vis[next] && !fin[next]) return true;
        if(vis[next]) continue;
        if (dfs(edge, next)) {
            return true;
        }
    }
    fin[curr]=1;
    return false;
}

void solve(int n, int m, const vector<int>& a, const vector<int>& b, const vector<int> c)
{
    g.clear(); g.resize(n);
    int i;
    for(i=0; i<m; i++) {
        g[a[i]].push_back(make_pair(b[i],i));
        if(c[i]==1) g[b[i]].push_back(make_pair(a[i],i));
    }
    for(i=0; i<n; i++) {
        vis.clear(); vis.resize(n);
        fin.clear(); fin.resize(n);
        bool ret=dfs(-1,i);
        if(ret){
            printf("Yes\n"); return;
        }
    }
    printf("No\n");
    return;
}

int main(int argc, char* argv[])
{
    int n,m;
    scanf("%d%d", &n, &m);
    vector<int> a(m),b(m),c(m);
    int i;
    for(i=0; i<m; i++) {
        scanf("%d%d%d", &a[i], &b[i],&c[i]); a[i]--; b[i]--;
    }
	solve(n, m, a, b, c);
	return 0;
}