#include <bits/stdc++.h>
using namespace std;
char maze[510][510];
bool used[510][510];
int n, m, K;
bool valid(int x, int y) {
  if (x >= 0 && x < n && y >= 0 && y < m)
    return true;
  else
    return false;
}
int dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};
void dfs(int u, int v) {
  used[u][v] = true;
  K--;
  for (int i = 0; i < 4; i++) {
    if (K) {
      int x, y;
      x = u + dx[i];
      y = v + dy[i];
      if (valid(x, y))
        if (maze[x][y] == '.')
          if (!used[x][y]) dfs(x, y);
    }
  }
}
int main() {
  memset(used, false, sizeof used);
  int i, j;
  scanf("%d %d %d", &n, &m, &K);
  for (int i = 0; i < n; i++) scanf("%s", maze[i]);
  vector<pair<int, int> > safe;
  for (int i = 0; i < n; i++)
    for (int j = 0; j < m; j++)
      if (maze[i][j] == '.') safe.push_back(pair<int, int>(i, j));
  K = safe.size() - K;
  dfs(safe[0].first, safe[0].second);
  for (int i = 0; i < safe.size(); i++)
    if (!used[safe[i].first][safe[i].second])
      maze[safe[i].first][safe[i].second] = 'X';
  for (int i = 0; i < n; i++) puts(maze[i]);
  return 0;
}
