#include <bits/stdc++.h>
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define dbg(x) cerr << #x << " = " << x << "\n"
#define fast_io ios_base::sync_with_stdio(0); cin.tie(0); cout.tie()
using namespace std;
using ll = long long;
using ld = long double;
const int N = int(1e6) + 500;
int A, B;
queue <string> q;
vector <string> res;
int main() {
fast_io;
cin >> A >> B;
A = max(A, (B + 1) / 2);
q.push("");
while (int(res.size()) < A) {
string t = q.front();
q.pop();
for (int i = 0; i < 26; ++i) {
res.push_back(t + char(i + 'a'));
q.push(t + char(i + 'a'));
}
}
for (int i = 0; i < min(B, int(res.size())); ++i)
cout << res[i] << " ";
}
