#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  k = min(k, 26);
  string s = "ab";
  for (int i = 0; i < k - 2; i++) {
    s += char(99 + i);
  }
  string s1 = "";
  for (int i = 0; i < n / k; i++) {
    s1 += s;
  }
  for (int i = 0; i < n % k; i++) {
    s1 = s1 + s[i];
  }
  cout << s1 << endl;
  return 0;
}
