program RemoveNonCommonLetters;
function RemoveNonCommonLetters(const word1, word2: string): string;
var
i: Integer;
begin
RemoveNonCommonLetters := '';
for i := 1 to Length(word1) do
begin
if Pos(word1[i], word2) > 0 then
RemoveNonCommonLetters := RemoveNonCommonLetters + word1[i];
end;
end;
var
word1, word2, resultStr: string;
begin
word1 := 'forest';
word2 := 'tor';
resultStr := RemoveNonCommonLetters(word1, word2);
WriteLn(resultStr);
end.
(*
run:
ort
*)