#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  int n, k, j = 0;
  cin >> n >> k;
  string word;
  while (j < n)
    for (int i = 97; i != 97 + k && j < n; ++i, ++j) {
      word = i;
      cout << word << flush;
    }
  return 0;
}
