$_=<>,chomp;
$m="─────";
print

" "x($_*2-2),"╭─╨─╨─╮\n",

$_-1? "  "x($_-2)."╭─┴$m┴─╮\n" : "└$m┘" ,

"  "x($_-2)."│         │\n"x($_>1),

$_>2?"╭─┴$m────┴─╮\n":"└─$m───┘"x($_>1),

"│             │\n└$m$m───┘"x($_>2)