#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
#define fi first
#define se second
#define eb emplace_back
#define bp __builtin_parity
#define y1 yyl
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<pii> vp;

int read() {
	int x=0,w=1; char c=getchar();
	while(!isdigit(c)) {if(c=='-') w=-1; c=getchar();}
	while(isdigit(c)) {x=x*10+c-'0'; c=getchar();}
	return x*w;
}

int n,k,deg[509];
vp ans;

void work(int n,int k) {
	if(n==k+1) {
		rep(i,1,n) {
			rep(j,i+1,n+1-i) {
				ans.eb(pii(i,j));
			}
		}
	} else {
		ans.eb(pii(1,n));
		work(n-1,k);
	}
}

signed main() {
	n=read(), k=read();
	if(n==1) {
		return puts("YES\n0"), 0;
	}
	if(n==2&&k==1) {
		return puts("YES\n1\n1 2\n"), 0;
	}
	if(n==k) return puts("NO"), 0;
	puts("YES");
	if(k==1) {
		printf("%d\n",n);
		rep(i,1,n) printf("%d %d\n",i,i%n+1);
		return 0;
	}
	work(n,k);
	printf("%d\n",(int)ans.size());
	for(auto e:ans) printf("%d %d\n",e.fi,e.se);
		/*
	for(auto e:ans) deg[e.fi]++, deg[e.se]++;
	sort(deg+1,deg+n+1); int cnt=unique(deg+1,deg+n+1)-deg-1;
	assert(cnt==k);
		*/
	return 0;
}