#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n, k;
  cin >> n >> k;
  char def = 'a';
  int pos = 0;
  string ans = "";
  for (int i = 0; i < n; i++) {
    ans += def + pos;
    pos = (pos + 1) % k;
  }
  cout << ans;
  return 0;
}
