#include <bits/stdc++.h>
using namespace std;
const long long N = 3e5 + 5;
vector<long long> adj[N];
vector<pair<long long, long long> > lol[N];
long long x[N], y[N], z[N], vis[N], tin[N], low[N], bridge[N], comp[N],
    artificat[N], depth[N], par[N], path[N], timer, cur;
void dfs1(long long node, long long prvId) {
  vis[node] = 1;
  tin[node] = low[node] = ++timer;
  for (auto &id : adj[node]) {
    if (id == prvId) continue;
    long long v = x[id] ^ y[id] ^ node;
    if (!vis[v])
      dfs1(v, id), low[node] = min(low[node], low[v]);
    else
      low[node] = min(low[node], tin[v]);
    if (low[v] > tin[node]) bridge[id] = 1;
  }
}
void dfs2(long long node) {
  comp[node] = cur;
  vis[node] = 1;
  for (auto &id : adj[node]) {
    if (bridge[id]) continue;
    if (z[id]) artificat[cur] = 1;
    long long v = x[id] ^ y[id] ^ node;
    if (!vis[v]) dfs2(v);
  }
}
void dfs3(long long node, long long pr) {
  depth[node] = depth[pr] + 1;
  par[node] = pr;
  for (auto &ele : lol[node])
    if (ele.first != pr) path[ele.first] = ele.second, dfs3(ele.first, node);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long n, m;
  cin >> n >> m;
  for (long long i = 1; i <= m; i++) {
    cin >> x[i] >> y[i] >> z[i];
    adj[x[i]].push_back(i);
    adj[y[i]].push_back(i);
  }
  dfs1(1, 0);
  for (long long i = 1; i <= n; i++) vis[i] = 0;
  for (long long i = 1; i <= n; i++)
    if (!vis[i]) cur++, dfs2(i);
  for (long long i = 1; i <= m; i++) {
    if (bridge[i]) {
      lol[comp[x[i]]].push_back({comp[y[i]], z[i]});
      lol[comp[y[i]]].push_back({comp[x[i]], z[i]});
    }
  }
  dfs3(1, 0);
  long long s, t;
  cin >> s >> t;
  s = comp[s], t = comp[t];
  while (s != t) {
    if (depth[s] < depth[t]) swap(s, t);
    if (artificat[s] || path[s]) return cout << "YES", 0;
    s = par[s];
  }
  cout << (artificat[s] ? "YES" : "NO");
}
