#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k, i, j;
  cin >> n >> k;
  string sr[1000];
  for (i = 1; i <= n; i++) {
    sr[i] = "Aashik";
    sr[i][0] += i / 26;
    sr[i][1] += i % 26;
  }
  for (i = 1; i <= n - k + 1; i++) {
    string j;
    cin >> j;
    if (j[0] == 'N') sr[i + k - 1] = sr[i];
  }
  for (i = 1; i <= n; i++) cout << sr[i] << " ";
  return 0;
}
