var a:array[0..25] of integer; i,j,n,m,p:integer; ch:char;

begin
readln(m,n,p);

for i:=1 to n do begin
for j:=1 to m do begin
read(ch);
inc(a[ord(ch)-ord('A')]);
end;
readln;
end;

for i:=1 to p do begin
while not eoln do begin
read(ch);
dec(a[ord(ch)-ord('A')]);
end;
readln; end;

for i:=0 to 25 do
if a[i]>0 then for j:=1 to a[i] do write(chr(ord('A')+i));
end.

var
  a:array[1..26]of integer;
  n,m,i,j,p:integer;
  k:char;
  o:string;
begin
  readln(n,m,p);
  for n:=1 to n do
    begin
      for m:=1 to m do
        begin
          read(k);
          i:=ord(k)-64;
          inc(a[i]);
        end;
      readln;
    end;
  for p:=1 to p do
    begin
      readln(o);
      for i:=1 to length(o) do
        begin
          j:=ord(o[i])-64;
          dec(a[j]);
        end;
    end;
  for i:=1 to 26 do
    if a[i]<>0 then
      begin
        for j:=1 to a[i] do
          write(chr(i+64));
      end;
end.

good