#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
#define all(x) x.begin(), x.end()
#define kill(x) return cout << x << endl, 0
#define X first
#define Y second
#define sep ' '
#define endl '\n'
ll pw(ll a, ll b, ll mod) {
if (!b) return 1;
if (b & 1) return a * pw(a * a % mod, b / 2, mod) % mod;
return pw(a * a % mod, b / 2, mod) % mod;
}
const ll N = 1e5 + 10;
const ll MOD = 1e9 + 7;
const ll INF = 1e18;
int L, R;
int main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
cin >> L >> R;
for (int i = 0; i < R; i++) {
string s;
int now = i;
for (int j = 0; j < 4; j++) {
s.push_back((now % 26) + 'a');
now /= 26;
}
cout << s << sep;
}
cout << endl;
return 0;
}
