#include <bits/stdc++.h>
using namespace std;
const int maxn = 1000000 + 10;
int n, l, k;
char s[maxn];
string ans[1010];
int len[1010];
int main() {
  scanf("%d%d%d", &n, &l, &k);
  scanf("%s", s + 1);
  sort(s + 1, s + n * l + 1);
  int cur = 1;
  int L = 1;
  while (1) {
    for (int i = L; i <= k; i++) {
      ans[i] = ans[i] + s[cur];
      len[i]++;
      cur++;
    }
    if (len[k] == l) break;
    while (L + 1 <= k && ans[L][len[k] - 1] != ans[k][len[k] - 1]) L++;
  }
  for (int i = 1; i <= k; i++) {
    for (int j = len[i] + 1; j <= l; j++) {
      ans[i] = ans[i] + s[cur];
      cur++;
    }
  }
  cur = n * l;
  for (int j = 1; j <= l; j++) {
    for (int i = k + 1; i <= n; i++) {
      ans[i] = ans[i] + s[cur];
      cur--;
    }
  }
  sort(ans + 1, ans + n + 1);
  for (int i = 1; i <= n; i++) cout << ans[i] << endl;
  return 0;
}
