#include <bits/stdc++.h>
using namespace std;
const int MOD = (int)1e9 + 7;
const int INF = (int)1e9;
const long long LINF = (long long)1e18;
const long double PI = acos((long double)-1);
const long double EPS = 1e-9;
long long gcd(long long a, long long b) {
  long long r;
  while (b) {
    r = a % b;
    a = b;
    b = r;
  }
  return a;
}
long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
long long fpow(long long n, long long k, int p = MOD) {
  long long r = 1;
  for (; k; k >>= 1) {
    if (k & 1) r = r * n % p;
    n = n * n % p;
  }
  return r;
}
template <class T>
inline int chkmin(T& a, const T& val) {
  return a > val ? a = val, 1 : 0;
}
template <class T>
inline int chkmax(T& a, const T& val) {
  return a < val ? a = val, 1 : 0;
}
void addmod(int& a, int val, int p = MOD) {
  if ((a = (a + val)) >= p) a -= p;
}
void submod(int& a, int val, int p = MOD) {
  if ((a = (a - val)) < 0) a += p;
}
int mult(int a, int b, int p = MOD) { return (long long)a * b % p; }
int inv(int a, int p = MOD) { return fpow(a, p - 2, p); }
const int maxn = 300010;
int n, m, a, b;
vector<pair<pair<int, int>, int> > edges;
vector<pair<int, int> > adj[maxn];
int cnt;
int num[maxn];
int low[maxn];
int val[maxn];
int dj[maxn];
int hs[maxn];
void init() {
  for (int i = (0); i < (n); i++) dj[i] = i;
}
int find(int u) { return dj[u] == u ? dj[u] : dj[u] = find(dj[u]); }
void join(int u, int v) { dj[find(u)] = dj[find(v)]; }
void dfs(int u, int p = -1) {
  num[u] = low[u] = ++cnt;
  for (int i = (0); i < (int((adj[u]).size())); i++) {
    int v = adj[u][i].first;
    if (v != p) {
      if (num[v]) {
        chkmin(low[u], num[v]);
      } else {
        dfs(v, u);
        if (low[v] < num[v]) {
          join(u, v);
        }
        chkmin(low[u], low[v]);
      }
    }
  }
}
void dfs2(int u, int k, int p = -1) {
  val[u] = k;
  for (int i = (0); i < (int((adj[u]).size())); i++) {
    int v = adj[u][i].first;
    int w = adj[u][i].second;
    if (v != p) {
      dfs2(v, k | w | hs[v], u);
    }
  }
}
void solve() {
  cin >> n >> m;
  for (int i = (0); i < (m); i++) {
    int u, v, w;
    cin >> u >> v >> w;
    u--;
    v--;
    adj[u].push_back(make_pair(v, w));
    adj[v].push_back(make_pair(u, w));
    edges.push_back(make_pair(make_pair(u, v), w));
  }
  cin >> a >> b;
  a--;
  b--;
  init();
  dfs(0);
  for (int i = (0); i < (n); i++) adj[i].clear();
  for (int i = (0); i < (int((edges).size())); i++) {
    int u = edges[i].first.first;
    int v = edges[i].first.second;
    int w = edges[i].second;
    int p = find(u);
    int q = find(v);
    if (p != q) {
      adj[p].push_back(make_pair(q, w));
      adj[q].push_back(make_pair(p, w));
    } else if (w) {
      hs[p] = 1;
    }
  }
  a = find(a);
  b = find(b);
  dfs2(a, hs[a]);
  val[b] ? cout << "YES\n" : cout << "NO\n";
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  solve();
  return 0;
}
