#include <bits/stdc++.h>
using namespace std;
int main(int argc, char** argv) {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n, k;
  cin >> n >> k;
  for (int i = 0; i < n; ++i) cout << (char)('a' + (i % k));
  cout << endl;
  return 0;
}
