#include #include using namespace std; using ll = long long; int main() { // s-t みたいな時、Kが奇数なら行き来するだけでいい?? // K=2nかつs, t が孤立してる時だけ無理? ll N, M, K, s, t; cin >> N >> M >> K >> s >> t; vector U(M), V(M); unordered_set ss, ts; for (int i=0;i> U[i] >> V[i]; if (U[i]==s) ss.insert(V[i]); if (V[i]==s) ss.insert(U[i]); if (U[i]==t) ts.insert(V[i]); if (V[i]==t) ts.insert(U[i]); } bool condition_x = true; if (K%2L==0L && ss.empty() && ts.empty()) { cout << "No" << endl; } else if (N==2 && K%2L==0L) { cout << "No" << endl; } else if (K%2L==0L && ss.contains(t) && ss.size()==1 && ts.size()==1 && condition_x) { cout << "No" << endl; } else { cout << "Yes" << endl; } }