#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  int a = min(k, 26) + 97;
  vector<char> b;
  for (int i = 97; i < a; i++) {
    b.push_back((char)i);
  }
  string key = "";
  for (int i = 0; i < b.size(); i++) key += b[i];
  int c = n - k, j = 0;
  while (true) {
    key += b[j];
    j++;
    if (j > b.size() - 1) j = 0;
    c--;
    if (c <= 0) break;
  }
  if (key.size() > n) {
    key.erase(key.size() - 1, 1);
  }
  cout << key;
  return 0;
}
