#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  string out, chr;
  cin >> n >> k;
  for (int i = 0; i < k; ++i) chr += 'a' + i;
  for (int i = 0; i < n; ++i) out += chr[i % k];
  cout << out;
  return 0;
}
