#include<bits/stdc++.h>
using namespace std;
#define int long long
#define fi first
#define se second
#define lowbit(x) (x&(-x))
typedef long long ll;
//typedef unsigned long long ull;
const int N = 1e6 + 10, M = 1e5, mod = 998244353;
int n, m, k;
int res,ans;
int num[N];
string s;
void dfs(int id,int c1,int c2,int la)
{
	if(res>=100||c1>m||c2>m) return;
	if(id==n+1)
	{
		if(c1*c2==ans)
		{
			res++;
			for(auto it:s)
			{
				if(it=='0') cout<<'b';
				else cout<<'r';
			}
			cout<<endl;
		}
		return;
	}
	if(la==0)
	{
		s[id-1]='0';
		dfs(id+1,c1+1,c2,0);
		s[id-1]='1';
		dfs(id+1,c1,c2+1,1);
	}
	else
	{
		s[id-1]='0';
		dfs(id+1,c1,c2+1,1);
		s[id-1]='1';
		dfs(id+1,c1+1,c2,0);
	}
}

void solve() {
	cin>>n;
	for(int i=1;i<=n;i++) s+='0';
	m=(n+2)/2;
	ans=m*(n-m+1);
	if(n==1) ans=1;
	cout<<ans<<endl;
	dfs(1,1,0,0);
}

signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int T;
	T = 1;
	//cin >> T;
	while (T--) solve();
	return 0;
}
/*

*/