#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
bool compare(pair<int, int> a, pair<int, int> b) {
  return (a.second > b.second);
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, k, cnt = 0, cnt2 = 0, cnt3 = 0;
  cin >> n >> k;
  for (int i = 97; i <= 122; ++i) {
    if (cnt < n && cnt2 < k) {
      cout << (char)i;
      ++cnt, ++cnt2;
    } else if (cnt < n && cnt2 >= k) {
      cout << (char)(97 + cnt3);
      i--, ++cnt, ((cnt3 < cnt2 - 1) ? ++cnt3 : cnt3 = 0);
    }
    if (cnt < n && i == 122) i -= 26;
  }
}
