#include using namespace std; using lint = long long; using pint = pair; using plint = pair; struct fast_ios { fast_ios(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_; #define ALL(x) (x).begin(), (x).end() #define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i=i##_begin_;i--) #define REP(i, n) FOR(i,0,n) #define IREP(i, n) IFOR(i,0,n) template void ndarray(vector &vec, int len) { vec.resize(len); } template void ndarray(vector &vec, int len, Args... args) { vec.resize(len); for (auto &v : vec) ndarray(v, args...); } template void ndfill(V &x, const T &val) { x = val; } template void ndfill(vector &vec, const T &val) { for (auto &v : vec) ndfill(v, val); } template bool chmax(T &m, const T q) { if (m < q) {m = q; return true;} else return false; } template bool chmin(T &m, const T q) { if (m > q) {m = q; return true;} else return false; } template pair operator+(const pair &l, const pair &r) { return make_pair(l.first + r.first, l.second + r.second); } template pair operator-(const pair &l, const pair &r) { return make_pair(l.first - r.first, l.second - r.second); } template vector srtunq(vector vec) { sort(vec.begin(), vec.end()), vec.erase(unique(vec.begin(), vec.end()), vec.end()); return vec; } template istream &operator>>(istream &is, vector &vec) { for (auto &v : vec) is >> v; return is; } template ostream &operator<<(ostream &os, const vector &vec) { os << '['; for (auto v : vec) os << v << ','; os << ']'; return os; } #if __cplusplus >= 201703L template istream &operator>>(istream &is, tuple &tpl) { std::apply([&is](auto &&... args) { ((is >> args), ...);}, tpl); return is; } template ostream &operator<<(ostream &os, const tuple &tpl) { std::apply([&os](auto &&... args) { ((os << args << ','), ...);}, tpl); return os; } #endif template ostream &operator<<(ostream &os, const deque &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os; } template ostream &operator<<(ostream &os, const set &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; } template ostream &operator<<(ostream &os, const unordered_set &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; } template ostream &operator<<(ostream &os, const multiset &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; } template ostream &operator<<(ostream &os, const unordered_multiset &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; } template ostream &operator<<(ostream &os, const pair &pa) { os << '(' << pa.first << ',' << pa.second << ')'; return os; } template ostream &operator<<(ostream &os, const map &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; } template ostream &operator<<(ostream &os, const unordered_map &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; } #ifdef HITONANODE_LOCAL #define dbg(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") " << __FILE__ << endl #else #define dbg(x) #endif template struct ShortestPath { int V, E; int INVALID = -1; std::vector>> to; ShortestPath() = default; ShortestPath(int V) : V(V), E(0), to(V) {} void add_edge(int s, int t, T len) { assert(0 <= s and s < V); assert(0 <= t and t < V); to[s].emplace_back(t, len); E++; } std::vector dist; std::vector prev; // Dijkstra algorithm // Complexity: O(E log E) void Dijkstra(int s) { assert(0 <= s and s < V); dist.assign(V, std::numeric_limits::max()); dist[s] = 0; prev.assign(V, INVALID); using P = std::pair; std::priority_queue, std::greater

> pq; pq.emplace(0, s); while(!pq.empty()) { T d; int v; std::tie(d, v) = pq.top(); pq.pop(); if (dist[v] < d) continue; for (auto nx : to[v]) { T dnx = d + nx.second; if (dist[nx.first] > dnx) { dist[nx.first] = dnx, prev[nx.first] = v; pq.emplace(dnx, nx.first); } } } } // Bellman-Ford algorithm // Complexity: O(VE) bool BellmanFord(int s, int nb_loop) { assert(0 <= s and s < V); dist.assign(V, std::numeric_limits::max()); dist[s] = 0; prev.assign(V, INVALID); for (int l = 0; l < nb_loop; l++) { bool upd = false; for (int v = 0; v < V; v++) { if (dist[v] == std::numeric_limits::max()) continue; for (auto nx : to[v]) { T dnx = dist[v] + nx.second; if (dist[nx.first] > dnx) { dist[nx.first] = dnx, prev[nx.first] = v; upd = true; } } } if (!upd) return true; } return false; } // Warshall-Floyd algorithm // Complexity: O(E + V^3) std::vector> dist2d; void WarshallFloyd() { dist2d.assign(V, std::vector(V, std::numeric_limits::max())); for (int i = 0; i < V; i++) { dist2d[i][i] = 0; for (auto p : to[i]) dist2d[i][p.first] = min(dist2d[i][p.first], p.second); } for (int k = 0; k < V; k++) { for (int i = 0; i < V; i++) { if (dist2d[i][k] = std::numeric_limits::max()) continue; for (int j = 0; j < V; j++) { if (dist2d[k][j] = std::numeric_limits::max()) continue; dist2d[i][j] = min(dist2d[i][j], dist2d[i][k] + dist2d[k][j]); } } } } }; int main() { int N, M, P, S, G; cin >> N >> M >> P >> S >> G; S--, G--; ShortestPath graph(N * 2); while (M--) { int u, v; cin >> u >> v; u--, v--; REP(_, 2) { graph.add_edge(u, v + N, 1); graph.add_edge(v + N, u, 1); swap(u, v); } } graph.Dijkstra(S); auto dS = graph.dist; graph.Dijkstra(G); auto dG = graph.dist; vector ret; REP(i, N) { bool flg = false; REP(d, 2) REP(e, 2) { lint D = lint(dS[i + d * N]) + dG[i + e * N]; if (D <= P and (P - D) % 2 == 0) flg = true; } if (flg) ret.emplace_back(i + 1); } if (ret.empty()) puts("-1"); else { cout << ret.size() << '\n'; for (auto x : ret) cout << x << '\n'; } }