#include <iostream>
#include<vector>
#include<algorithm>
#include<string>
#include<map>
#include<set>
#include<stack>
#include<queue>
#include<math.h>
using namespace std;
typedef long long ll;
#define int long long
#define double long double
typedef vector<int> VI;
typedef pair<int, int> pii;
typedef vector<pii> VP;
typedef vector<string> VS;
typedef priority_queue<int> PQ;
template<class T>bool chmax(T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b < a) { a = b; return 1; } return 0; }
#define fore(i,a) for(auto &i:a)
#define REP(i,n) for(int i=0;i<n;i++)
#define eREP(i,n) for(int i=0;i<=n;i++)
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define eFOR(i,a,b) for(int i=(a);i<=(b);++i)
#define SORT(c) sort((c).begin(),(c).end())
#define rSORT(c) sort((c).rbegin(),(c).rend())
#define LB(x,a) lower_bound((x).begin(),(x).end(),(a))
#define UB(x,a) upper_bound((x).begin(),(x).end(),(a))
#define INF 1000000000
#define LLINF 9223372036854775807
#define mod 1000000007
#define eps 1e-12 
//priority_queue<int,vector<int>, greater<int> > q2;

int N, M, P, s, g;
vector<VI> G;
VI d;
int q[200005];

void bfs(int s) {
	REP(i, N)d[i] = INF;
	int qh = 0, qt = 0;
	q[qh++] = s;
	d[s] = 0;
	while (qt < qh) {
		int x = q[qt++];
		for (int y : G[x]) {
			if (d[y] == INF) {
				d[y] = d[x] + 1;
				q[qh++] = y;
			}
		}
	}
}



signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	cin >> N >> M >> P >> s >> g;
	G.resize(N);
	d.resize(N);
	s--;
	g--;
	REP(i, M) {
		int v, u; cin >> u >> v;
		u--;
		v--;
		G[v].push_back(u);
		G[u].push_back(v);
	}
	VI ans;
	bfs(s);
	VI dis1 = d;
	bfs(g);
	VI dis2 = d;

	REP(i, N) if (dis1[i] + dis2[i] == P)ans.push_back(i);

	if (ans.size() == 0) {
		cout << -1 << endl;
		return 0;
	}
	SORT(ans);
	cout << ans.size() << endl;
	fore(i, ans)cout << i + 1 << '\n';

	return 0;
}