#include <bits/stdc++.h>
using namespace std;
char s[3];
int a[1000003];
int main() {
  int n, k;
  while (~scanf("%d%d", &n, &k)) {
    int m = n - k + 1;
    for (int i = 1; i <= n; i++) a[i] = i;
    for (int i = k; i <= n; i++) {
      scanf("%s", s);
      if (s[0] == 'N') a[i] = a[i - k + 1];
    }
    for (int i = 1; i <= n; i++) {
      if (i != 1)
        printf(" %c%c", a[i] / 26 + 'A', a[i] % 26 + 'a');
      else
        printf("%c%c", a[i] / 26 + 'A', a[i] % 26 + 'a');
    }
    printf("\n");
  }
}
