#include <bits/stdc++.h>
#define REP(i, n) for(int i = 0;i < n;i++)
#define ll long long
using namespace std;
//typedef vector<unsigned int>vec;
//typedef vector<ll>vec;
//typedef vector<vec> mat;
typedef pair<int, int> P;
typedef pair<ll,ll> LP;
const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
const int INF = 1000000000;
const ll LINF = 1000000000000000000;//1e18
const ll  MOD = 1000000007;
const double PI = acos(-1.0);
const double EPS = 1e-10;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
//template<class T> inline void add(T &a, T b){a = ((a+b) % MOD + MOD) % MOD;};


int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N, M;
    cin >> N >> M;
    vector<int> a, b;
    vector<int> c;
 
    REP(i,M){
        int u, v, e;
        cin >> u >> v >> e;
        a.push_back(u), b.push_back(v), c.push_back(-1);
        if(e == 1) a.push_back(v), b.push_back(u), c.push_back(-1);
    }
    vector<ll> dist(N);
 
    REP(i,N) dist[i] = INF;
 
    dist[0] = 0;
    for(int loop=0;loop<N;++loop){
        for(int i=0;i<(int)a.size();++i){
            if(dist[a[i]-1]==INF) continue;
 
            if(dist[b[i]-1] > dist[a[i]-1]+c[i]) dist[b[i]-1] = dist[a[i]-1] + c[i];
        }
    }
 
    vector<bool> negative(N,0);
    for(int loop=0;loop<N;++loop){
        for(int i=0;i<(int)a.size();++i){
            if(dist[a[i]-1]==INF) continue;
 
            if(dist[b[i]-1] > dist[a[i]-1]+c[i]){
                dist[b[i]-1] = dist[a[i]-1] + c[i];
                negative[b[i]-1] = true;
            }
 
            if(negative[a[i]-1]==true) negative[b[i]-1]=true;
        }
    }

    int cnt = 0;
    REP(i,N) if(negative[i]) cnt++;
    if(cnt == N) cout << "Yes" << endl;
    else cout << "No" << endl;
}