#include <bits/stdc++.h>
using namespace std;
int n, k;
int main() {
  cin >> n >> k;
  string ans = "";
  for (int i = 1, character = 0; i <= n; i++, character++) {
    if (character == k) character = 0;
    ans += character + 'a';
  }
  cout << ans;
  return 0;
}
