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¹æ¹ý1 ¶
\newcommand\hello[2][\@empty]{
\ifx#1\@empty
\def\temp@val{1 : }
\else
\def\temp@val{#1 : }
\fi
¹æ¹ý2 ¶
\@ifnextchar ¸¦ ÀÌ¿ëÇؼ µÎ°³ÀÇ ÇÔ¼ö¸¦ ºÐ¸®Çؼ »ç¿ëÇÏ´Â ¹æ½Ä
\makeatletter
\def\PicTure{\@ifnextchar[\@pic@ture\@@pic@@ture}
\def\@pic@ture[#1]#2{\includegraphics[width=#1cm]{#2}}
\def\@@pic@@ture#1{\includegraphics{#1}}
\makeatother