/* Thu Mar 25 22:25:31 JST 2004 */
/* Thu Mar 25 23:24:46 JST 2004 */
#include <stdio.h>

int w, h;
char s[32][64];
char superemum[32][32], infimum[32][32];

void simple_or()
{
  int i, j;
  for (i = 0; i < h+1; i++) {
    for (j = 0; j < 2*w+1; j++) {
      if (s[i][j+2*w+2] != ' ') { infimum[i][j] = s[i][j+2*w+2]; }
      else if (s[i][j] != ' ')  { infimum[i][j] = s[i][j]; }
      else                      { infimum[i][j] = ' '; }
    }
  }
}

void simple_and()
{
  int i, j;
  for (i = 0; i < h+1; i++) {
    for (j = 0; j < 2*w+1; j++) {
      if (s[i][j+2*w+2] == s[i][j]) { superemum[i][j] = s[i][j]; }
      else                          { superemum[i][j] = ' '; }
    }
  }
}

void replace(char x, char y)
{
  int i, j;
  for (i = 0; i < h+1; i++) {
    for (j = 0; j < 2*w+1; j++) {
      if (superemum[i][j] == x) { superemum[i][j] = y; }
    }
  }
}

int down(int y, int x)
{
  int i = y, j = x, del = 0;

  if (superemum[i-1][j-1] != '_' || superemum[i-1][j+1] != '_') {
    del = 1;
  }

  for (i = y; ; i++) {
    if (superemum[i][j] != '|') {
      replace('@', ' '); return 1;
    }
    superemum[i][j] = '@';
    if (superemum[i][j-1] == '_' && superemum[i][j+1] == '_') {
      if (del) { replace('@', ' '); return 1; }
      else     { replace('@', '!'); return 0; }
    }
  }
}

int right(int y, int x)
{
  int i = y, j = x, del = 0;

  if (superemum[i][j-1] != '|' || superemum[i+1][j-1] != '|') {
    del = 1;
  }

  for (j = x; ; j += 2) {
    if (superemum[i][j] != '_') {
      replace('@', ' '); return 1;
    }
    superemum[i][j] = '@';
    if (superemum[i][j+1] == '|' && superemum[i+1][j+1] == '|') {
      if (del) { replace('@', ' '); return 1; }
      else     { replace('@', '-'); return 0; }
    }
  }
}

int cut()
{
  int i, j, result = 0;
  for (i = 1; i < h+1; i++) {
    for (j = 1; j < 2*w; j++) {
      if (superemum[i][j] == '|') {
        result |= down(i, j);
      }
      if (i < h) {
        if (superemum[i][j] == '_') {
          result != right(i, j);
        }
      }
    }
  }
  replace('!', '|');
  replace('-', '_');
  return result;
}

int main()
{
  char tmp[1024];
  int icase, i, j;

  for (icase = 1; ; icase++) {
    gets(tmp); sscanf(tmp, "%d %d", &w, &h); if (w == 0 && h == 0) { break; }
    for (i = 0; i < h+1; i++) {
      gets(s[i]);
      infimum[i][2*w+1] = superemum[i][2*w+1] = '\0';
    }

    simple_or(); simple_and();
    while (cut()) { ; }

    printf("Case %d:\n", icase);
    for (i = 0; i < h+1; i++) {
      printf("%s %s\n", infimum[i], superemum[i]);
    }
    printf("\n");
  }
  return 0;
}