#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  char s[100];
  int m = 0, x = 0;
  for (int i = 97; i <= 122; i++) {
    s[m] = i;
    m++;
    k--;
    if (k == 0) break;
  }
  for (int i = m; i < n; i++) {
    s[i] = s[x];
    x++;
  }
  for (int i = 0; i < n; i++) cout << s[i];
}
