#include <bits/stdc++.h>
using namespace std;
int aps(int x) {
  if (x < 0)
    return -1 * x;
  else
    return x;
}
int main() {
  long long n, k;
  cin >> n >> k;
  char Counter = 'a';
  int maxx = Counter + k;
  int x = k;
  for (int i = 0; i < n; i++) {
    cout << Counter;
    Counter++;
    if (Counter == maxx) Counter = 'a';
  }
  return 0;
}
