#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k, ascii = 97;
  srand(time(0));
  cin >> n >> k;
  char pass[n];
  for (int i = 0; i < n; i++) {
    if (ascii >= 97 + k) ascii = 97;
    pass[i] = (char)ascii;
    cout << pass[i];
    ascii++;
  }
  return 0;
}
