/*

Author: Haze

2024/9/4

*/

#include <bits/stdc++.h>

#define irep(i, l, r) for(int i = (l); i <= (r); ++ i)
#define drep(i, r, l) for(int i = (r); i >= (l); -- i)
#define IOS ios::sync_with_stdio(false), cin.tie(nullptr);
using namespace std;
typedef long long ll;

inline ll readL() {
    ll s = 0;
    bool fl = false;
    char ch = (char) getchar();
    while (!isdigit(ch)) {
        if (ch == '-')fl = true;
        ch = (char) getchar();
    }
    while (isdigit(ch)) {
        s = s * 10 + (ch ^ 48);
        ch = (char) getchar();
    }
    return fl ? -s : s;
}

inline int read() {
    return (int) (readL());
}

const int mod = 1000000000 + 7;
const int itinf = 1000000999;
const ll llinf = 2e18;
const int N = 500099;
//203
ll f[210][210];

void solve2(int n, ll goal){
    //b for 0
//    f[0][0].insert(0);
    irep(len, 0, n){
        irep(i, 0, len){
            int j = len - i;
            //i odd, j even, pair
                f[i][j + 1]=max(f[i][j + 1], f[i][j] + i);
                f[j + 1][i] = max(f[j + 1][i], f[i][j] + j + 1);
        }
    }
//    irep(i, 1, 20){
//        irep(j, 1, 20){
//            cout << f[i][j] << ' ';
//        }
//        cout << endl;
//    }
    string ans;
    int counter = 0;
    ll res = goal;
    function<void(int, ll,ll)> dfs = [&](int i, ll even, ll odd){
//        cerr << i << ' ' << res << endl;

        if(i == n){
            cout << ans << '\n';
            ++ counter;
            if(counter == 100)exit(0);
            return;
        }
        //i odd, j even, pair

        //b
        ll remain = n - i - 1;
        ll R = res;
        for(ll codd = 0; codd <= remain; ++ codd){
            ll ceven = remain - codd;
            if(f[codd][ceven] + codd * even + ceven * odd + odd + codd == res){
                ans.push_back('b');
                res = R - odd;
                dfs(i + 1, even + 1, odd);
                res = R;
                ans.pop_back();
                break;
            }
        }

        for(ll codd = 0; codd <= remain; ++ codd){
            ll ceven = remain - codd;
            if(f[codd][ceven] + codd * odd + ceven * even + even + ceven + 1 == res){
                ans.push_back('r');
                res = R - even - 1;
                dfs(i + 1, odd, 1 + even);
                res = R;
                ans.pop_back();
                break;
            }
        }
    };
    dfs(0,0,0);
}

void solve() {


    map<int, vector<int>> mp;
    int n = readL();
    long long sums = 0;
    for (int i = 1; i <= n; i++) {
        sums += (n - i + 2) / 2;
    }
    cout << sums << endl;
    if (n > 203) {

        string s;

        int k = (n + 1) / 2;
        int left = n - k;
        for (int i = 0; i < left; i++) {
            s.push_back('b');
        }
        s.push_back('r');
        for (int i = 1; i < k; i++) {
            s.push_back('b');
        }
        vector<string> m = {s};
        s = "";
        for (int i = 0; i < left - 1; i++) {
            s.push_back('b');
        }
        s.push_back('r');

        for (int i = 0; i <= k; i++) {
            int lefts = k - i;
            int rr = min(k, lefts + 2);
            string ss = s;
            for (int j = 1; j <= lefts; j++) {
                ss.push_back('b');
            }
            for (int j = lefts + 1; j <= rr; j++) {
                ss.push_back('r');
            }
            for (int j = rr + 1; j <= k; j++) {
                ss.push_back('b');
            }
            m.push_back(ss);
            if (m.size() == 100) break;
        }
        for (auto j: m) {
            cout << j << endl;

        }
        return;
    }
    solve2(n, sums);

//    int maxs = 0;
//
//    {
//        //
//        ll z = (1ll << (n)) - 1;
//        vector<int> pre(n + 1);
//        for (int j = 1; j <= n; j++) {
//            pre[j] = (z >> (j - 1)) & 1;
//            pre[j] += pre[j - 1];
//        }
//        int sums = 0;
//        for (int j = 1; j <= n; ++j) {
//            for (int k = j; k <= n; k++) {
//                if ((pre[k] - pre[j - 1]) % 2 == 1) {
//                    sums++;
//                }
//            }
//        }
//        maxs = sums;
//
//    }

//    int f = (n - 1) / 2;
//    int to = (f + 2);
//    cerr << f << "  " << to << endl;
//    for (ll i = (1); i < (1 << n); i++) {
//
////        if (n > 20 && i > (1 << (18 + 1)))break;
//        vector<ll> pre(n + 1);
//
//        for (int j = 1; j <= n; j++) {
//            pre[j] = (i >> (j - 1)) & 1;
//            pre[j] += pre[j - 1];
//        }
//
//        int sums = 0;
//        for (int j = 1; j <= n; ++j) {
//            for (int k = j; k <= n; k++) {
//                if ((pre[k] - pre[j - 1]) % 2 == 1) {
//                    sums++;
//                }
//            }
//        }
//        if (sums == maxs) {
//
//            mp[sums].emplace_back(i);
//
//            if (mp[sums].size() > 100) break;
//        }
//    }
//    auto [i, j] = *mp.rbegin();
////    cerr << i << endl;
//    int t = 0;
//
//    for (auto k: j) {
//        t++;
//        if (t > 100) break;
//        cerr << bitset<12>(k) << "\n";
//    }
//    for (auto [i, j]: mp) {
//        cerr << i << " :\n";
//        for (auto k: j) cerr << bitset<20>(k) << "\n";
//        cerr << "\n";
//    }
}

int main() {
    // IOS
    int T = 1;
    while (T--) {
        solve();
    }
    return 0;
}