#include <iostream>
#include <vector>
using namespace std;
 
void DFS(int node, const vector<vector<int>>& adjList, vector<bool>& visited, int destination) {
    // If we've reached the destination, print YES and return
    if (node == destination) {
        cout << "YES" << endl;
        exit(0);  // Exit once we find the path
    }
 
    visited[node] = true;  // Mark the current node as visited
 
    // Explore all neighbors
    for (int neighbor : adjList[node]) {
        if (!visited[neighbor]) {
            DFS(neighbor, adjList, visited, destination);  // Recur for unvisited neighbors
        }
    }
}
 
int main() {
    int n, m;
    cin >> n >> m;  // Read number of nodes and edges
 
    vector<vector<int>> adjList(n);  // Adjacency list to store the graph
 
    // Read edges and build the graph
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        adjList[u].push_back(v);  // Add v to u's list
        adjList[v].push_back(u);  // Add u to v's list (undirected graph)
    }
 
    int start, destination;
    cin >> start >> destination;  // Read the start and destination nodes
 
    vector<bool> visited(n, false);  // Initialize the visited array
 
    DFS(start, adjList, visited, destination);  // Call DFS to check for path
 
    cout << "NO" << endl;  // If we reach here, there is no path
    return 0;
}
 

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