#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  int a = 97, t = n;
  string s = "";
  for (int i = 0; i < n; i++) {
    if (t >= k) {
      for (int j = 0; j < k; j++) s += a + j;
      i += k;
      i--;
      t -= k;
    } else {
      s += a;
      a++;
    }
  }
  cout << s << endl;
  return 0;
}
