#include <bits/stdc++.h>
int main() {
  int n, k;
  std::cin >> n;
  char *pass = new char[n];
  std::cin >> k;
  int t = 97;
  for (int i = 0; i < n; ++i) {
    if ((i >= k) && (i + t - k > 96)) {
      t -= k;
    }
    pass[i] = static_cast<char>(i + t);
  }
  for (int i = 0; i < n; ++i) {
    std::cout << pass[i];
  }
  std::cout << '\n';
  delete[] pass;
  return 0;
}
