#include <bits/stdc++.h>
using namespace std;
const int N = 300005, M = 2 * N;
struct Graph {
  int head[N], forword[M], from[M], to[M], cost[M], val[N], dis[N], vis[N], cnt,
      id, n;
  int dfn[N], low[N], instack[N], stack[N], belong[N], bcc, top;
  Graph() : cnt(0) {}
  void add(int a, int b, int c) {
    forword[++cnt] = head[a];
    from[cnt] = a;
    to[cnt] = b;
    cost[cnt] = c;
    head[a] = cnt;
    forword[++cnt] = head[b];
    from[cnt] = b;
    to[cnt] = a;
    cost[cnt] = c;
    head[b] = cnt;
  }
  void tarjan(int u, int fa) {
    int i;
    dfn[u] = low[u] = ++id;
    instack[u] = 1;
    stack[++top] = u;
    for (i = head[u]; i; i = forword[i]) {
      if (to[i] == fa) continue;
      if (!dfn[to[i]]) {
        tarjan(to[i], u);
        low[u] = min(low[to[i]], low[u]);
      } else if (instack[to[i]])
        low[u] = min(dfn[to[i]], low[u]);
    }
    if (dfn[u] == low[u]) {
      ++bcc;
      do {
        i = stack[top--];
        belong[i] = bcc;
        instack[i] = 0;
      } while (i != u);
    }
  }
  void do_bcc() {
    id = 0;
    top = 0;
    bcc = 0;
    for (int i = 1; i <= n; ++i)
      if (!dfn[i]) tarjan(i, 0);
  }
  void rebuild(Graph &out) {
    for (int i = 1; i <= cnt; i += 2)
      if (belong[from[i]] != belong[to[i]])
        out.add(belong[from[i]], belong[to[i]], cost[i]);
      else if (cost[i])
        out.val[belong[from[i]]] = 1;
  }
  bool calc(int x, int y) {
    queue<int> q;
    q.push(x);
    dis[x] = val[x];
    vis[x] = 1;
    while (!q.empty()) {
      int u = q.front(), i;
      q.pop();
      for (i = head[u]; i; i = forword[i])
        if (!vis[to[i]]) {
          if (dis[to[i]] < dis[u] + cost[i] + val[to[i]])
            dis[to[i]] = dis[u] + cost[i] + val[to[i]];
          q.push(to[i]);
          vis[to[i]] = 1;
        }
    }
    return dis[y];
  }
} base, ne;
int main() {
  int n, m, a, b, c;
  scanf("%d%d", &n, &m);
  base.n = n;
  for (int i = 1; i <= m; ++i) {
    scanf("%d%d%d", &a, &b, &c);
    base.add(a, b, c);
  }
  scanf("%d%d", &a, &b);
  base.do_bcc();
  base.rebuild(ne);
  puts(ne.calc(base.belong[a], base.belong[b]) ? "YES" : "NO");
  return 0;
}
