#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k, a = 97;
  cin >> n >> k;
  char w = static_cast<char>(a);
  for (int i = 0; n > i; i++) {
    cout << w;
    w++;
    if (w == 97 + k) {
      w = 97;
    }
  }
}
