#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using ld = long double;

ld dist(pair<ld,ld> a, pair<ld, ld> b){
	ld dx = a.first-b.first;
	ld dy = a.second-b.second;
	return sqrtl(dx*dx + dy*dy);
}

int main() {
	ll n;
	cin>>n;
	ld r;
	cin>>r;
	vector<pair<ld,ld>> planted;
	for(ll y=1;y<n;y++){
		for(ll x=1;x<n;x++){
			// check distance to boundary 
			ll b_dist = min({x,y,n-y,n-x});
			if((ld)b_dist<r) continue;
			// check distance to other planted trees
			ld p_dist = n;
			for(ll i=0;i<planted.size();i++){
				p_dist = min(p_dist, dist({x,y},planted[i]));
			}
			if(p_dist<2*r) continue;
			planted.push_back({x,y});
		}
	}
	cout<<planted.size()<<endl;
	for(ll i=0;i<planted.size();i++){
		cout<<planted[i].first<<" "<<planted[i].second<<endl;
	}
}