#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int t, n, sum1, sum2, f, d, i, x, k, y, z, w, sum, j, u, c, v, m, r;
  cin >> n >> k;
  x = 97;
  y = k;
  for (i = 0; i < n; i++) {
    cout << (char)x;
    x++;
    k--;
    if (k == 0) {
      x = 97;
      k = y;
    }
  }
  return 0;
}
