#include <iostream>
#include <vector>
#include <algorithm>
#include <cstdio>
#include <string>
#include <queue>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <sstream>
#include <math.h>

using namespace std;

int n, m, s, t, flow = 0;
vector<unordered_map<int, pair<int, int>>> g;
vector<bool> mark;

int dfs(int v, int d) {
    if (mark[v])
        return 0;
    mark[v] = true;
    if (v == t) {
        return d;
    }
    for (int u = n - 1; u >= 0; u--) {
        if (g[v][u].second > g[v][u].first) {
            int res = dfs(u, 1);
            if (res > 0) {
                g[v][u].first += 1;
                g[u][v].first -= 1;
                return 1;
            }
        }
    }
    return 0;
}

bool path(int v) {
    cout << v + 1 << ' ';
    if (v == t) {
        cout << endl;
        return true;
    }
    for (int u = 0; u < n; u++) {
        if (g[v][u].first > 0) {
            g[v][u].first -= 1;
            g[u][v].first += 1;
            if (path(u)) {
                return true;
            }
        }
    }
    return false;
}

int main() {
    cin >> n >> m;
    cin >> s >> t;
    s--;
    t--;
    g.resize(n);
    mark.resize(n);

    for (int i = 0; i < m; ++i) {
        int u, v, c = 1;
        cin >> u >> v;
        u--;
        v--;
        g[u][v].second += c;
        g[v][u].second = g[v][u].first = 0;
    }

    while (true) {
        fill(mark.begin(), mark.end(), false);
        int delta = dfs(s, INT_MAX);
        if (delta > 0) {
            flow += delta;
        } else {
            break;
        }
        if (flow == 2) {
            break;
        }
    }

    if (flow >= 2) {
        cout << "YES" << endl;
        path(s);
        path(s);
    } else {
        cout << "NO";
    }
}