#include <fstream>
#include <iostream>
#include <vector>
#include <deque>
#include <algorithm>

#define MAXN 100010


using namespace std;

ifstream fin("bfs.in");
ofstream fout("bfs.out");

int N, M, root, pathEnd;
int x, y;
vector<int> L[MAXN];
deque<int> q;
int d[MAXN];
int pred[MAXN];

void printPath(int s, int x)
{
    vector<int> path;
    for (int node = x; node != 0; node = pred[node])
        path.push_back(node);
    reverse(path.begin(), path.end());

    for (const auto el : path)
    {
        cout << el << " ";
    }
}

void bfs(int root, int pathEnd)
{
    q.push_back(root);
    d[root] = 1;
    
    while(!q.empty())
    {
        int node = q.front();
        for (const auto nextNode : L[node])
        {
            if (d[nextNode] == 0)
            {
                q.push_back(nextNode);
                d[nextNode] = d[node] + 1;
                pred[nextNode] = node;
            }
        }
        q.pop_front();
    }

    if (d[pathEnd] == 0) {
        cout << "No path from " << root << " to " << pathEnd << endl;
    } else {
        cout << "Shortest path from " << root << " to " << pathEnd << ": ";
        printPath(root, pathEnd);
    }
}

int main()
{
    fin >> N >> M >> root >> pathEnd;
    for (int i = 1; i <= M; i++)
    {
        fin >> x >> y;
        L[x].push_back(y);
    }

    bfs(root, pathEnd);

    for (int i = 1; i <= N; i++)
    {
        fout << d[i] - 1 <<  " ";
    }
    return 0;
}