#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k, x, i, p;
  char y;
  string ch = "";
  cin >> n >> k;
  for (i = 0; i < k; i++) {
    p = 97 + i;
    y = (char)p;
    ch += y;
  }
  if (n == k)
    cout << ch;
  else {
    x = n - k;
    i = 0;
    while (x--) {
      ch += ch[i];
      i++;
    }
    cout << ch;
  }
  return 0;
}
