#include #include #include #include #include #include #include #include #include #include using namespace std; #define int long long int MOD = 1000000007; int mid = 100000 / 2; signed main() { cin.tie(0); ios::sync_with_stdio(false); int N, M; cin >> N >> M; if (M >= N - 1 && M <= (N / 2)*(N - (N / 2))) { cout << "YES" << endl; for (int i = 0; i < N / 2; i++) { if (i > 0)cout << " "; cout << mid + i + 1; } for (int i = 0; i < N - (N / 2); i++) { cout << " " << mid - i; } cout << endl; int c = 0; set > st; for (int i = 0; i < N / 2; i++) { cout << i + 1 << " " << i + 1 + (N / 2) << endl; c++; st.insert(make_pair(i, i + (N / 2))); if (i != (N / 2) - 1 || (N % 2 != 0)) { cout << i + 1 << " " << i + 2 + (N / 2) << endl; c++; st.insert(make_pair(i, i + 1 + (N / 2))); } } for (int i = 0; i < N / 2; i++) { for (int j = N / 2; j < N; j++) { if (st.count(make_pair(i, j)) == 0) { cout << i + 1 << " " << j + 1 << endl; c++; } if (c == M)break; } if (c == M)break; } } else { cout << "NO" << endl; } }