#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, k, i, j;
  cin >> n >> k;
  string s = "abcdefghijklmnopqrstuvwxyz";
  char result[n];
  j = 0;
  for (i = 1; i <= n; i++) {
    result[i] = s[j];
    cout << result[i];
    if (i % k == 0) {
      j = 0;
    } else {
      j++;
    }
  }
}
