#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k, op, i, index = 0;
  cin >> n >> k;
  char ss[n - 1];
  op = k;
  i = 97;
  while (op--) {
    ss[index] = char(i);
    i++;
    index++;
  }
  if (n - k != 0) {
    for (int d = 0; d < n - k; d++) {
      ss[index] = ss[d];
      index++;
    }
  }
  for (int c = 0; c < n; c++) cout << ss[c];
}
