#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, m;
  cin >> n >> m;
  char arr[10001], j = 'a';
  for (int i = 0; i < n; i++, m--) {
    if (m > 0)
      arr[i] = j, j++;
    else {
      int t = i;
      for (int j = 0; i < n; i++, j++) {
        arr[i] = arr[j];
        if (j == t) j = 0;
      }
    }
  }
  for (int i = 0; i < n; i++) {
    cout << arr[i];
  }
  cout << endl;
  return 0;
}
