#include <bits/stdc++.h>
using namespace std;
int main() {
  string s = "abcdefghijklmnopqrstuvwxyz", m;
  int n, k;
  cin >> n >> k;
  for (int i = 0; i < k; i++) {
    m += s[i];
  }
  for (int i = 0; i < n; i++) {
    m += m[i];
    if (n == m.length()) break;
  }
  for (int i = 0; i < n; i++) cout << m[i];
  return 0;
}
