MODULE Rot13;

FROM STextIO IMPORT
    ReadString, WriteString, WriteLn;
FROM Strings IMPORT
    Length;

TYPE
    MyString = ARRAY [0..80] OF CHAR;

VAR
    S, T : MyString;

PROCEDURE Rot13(S : ARRAY OF CHAR; VAR T : ARRAY OF CHAR);
VAR
    I, J : CARDINAL;
BEGIN
    FOR I := 0 TO Length(S) - 1
        DO
            J := ORD(S[I]);
            IF ((J >= 65) AND (J <= 90)) THEN
                J := (J - 52) % 26 + 65;
            IF ((J >= 97) AND (J <= 122)) THEN
                J := (J - 84) % 26 + 97;
            T[I] := CHR(J);
        END;
END Rot13;

BEGIN
    WHILE NOT Eof
        DO
            ReadString(S);
            SkipLine;
            WriteLn;
            Rot13(S, T);
            WriteString(T);
            WriteLn;
        END;
END Rot13.