Why I got WA!!!HelpHelpHelp!This is my grogram:

var
  Save : array ['A' .. 'Z'] of longint;
  n, m, p, i, j : longint;
  c : char;
begin
  fillchar (Save, sizeof (Save), 0);
  readln (n, m, p);
  for i := 1 to n do
    begin
      for j := 1 to m do
        begin
          read (c);
          Save [c] := Save [c] + 1;
        end;
      readln;
    end;
  for i := 1 to p do
    begin
      for j := 1 to m do
        begin
          read (c);
          Save [c] := Save [c] - 1;
        end;
      readln;
    end;
  for c := 'A' to 'Z' do
    for i := 1 to Save [c] do
      write (c);
end.

var
  Save : array ['A' .. 'Z'] of longint;
  n, m, p, i, j : longint;
  c : char;
begin
  fillchar (Save, sizeof (Save), 0);
  readln (n, m, p);
  for i := 1 to n do
    begin
      for j := 1 to m do
        begin
          read (c);
          Save [c] := Save [c] + 1;
        end;
      readln;
    end;
  for i := 1 to p do
    begin
      read (c);
      while not (c in ['A' .. 'Z']) do
        read (c);
      while c in ['A' .. 'Z'] do
        begin
          Save [c] := Save [c] - 1;
          read (c);
        end;
    end;
  for c := 'A' to 'Z' do
    for i := 1 to Save [c] do
      write (c);
end.