import std.conv, std.functional, std.stdio, std.string; import std.algorithm, std.array, std.bigint, std.container, std.math, std.numeric, std.range, std.regex, std.typecons; import core.bitop; class EOFException : Throwable { this() { super("EOF"); } } string[] tokens; string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; } int readInt() { return readToken.to!int; } long readLong() { return readToken.to!long; } real readReal() { return readToken.to!real; } bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } } bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } } int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; } int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); } int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); } int N, M; void main() { try { for (; ; ) { N = readInt(); M = readInt(); if (N - 1 <= M && M <= (N / 2) * (N - N / 2)) { auto g = new bool[][](N / 2, N - N / 2); int m; foreach (i; 0 .. N / 2) foreach (j; 0 .. N - N / 2) { if (i == 0 || j == 0) { ++m; g[i][j] = true; } } foreach (i; 0 .. N / 2) foreach (j; 0 .. N - N / 2) { if (!g[i][j]) { if (m < M) { ++m; g[i][j] = true; } } } writeln("YES"); writeln(iota(1, N + 1).to!string.replaceAll(regex(`[\[\],]`), "")); foreach (i; 0 .. N / 2) foreach (j; 0 .. N - N / 2) { if (g[i][j]) { writeln(1 + i, " ", 1 + N / 2 + j); } } } else { writeln("NO"); } } } catch (EOFException e) { } }