#include <bits/stdc++.h>
using namespace std;
char getRandomChar(int b) {
  char c = 97 + b;
  return c;
}
int main() {
  int i = 0, n = 0, d = 0, x = 0, z = 0;
  cin >> n;
  cin >> d;
  string arr[d], a;
  for (i = 0; i < d; i++) {
    a = getRandomChar(i);
    arr[i] = a;
  }
  for (i = 0; i < n; i++) {
    cout << arr[x];
    x++;
    if (x == d) {
      x = 0;
    }
  }
  return 0;
}
