2ndlargest number bash progrm lang

echo "Enter value of a : "
read a
echo "Enter value of b : "
read b
echo "Enter value of c : "
read c

if [ $a -gt $b ]
   then
       if [ $a -gt $c ]
           then
           if [ $b -gt $c ]
           then
           echo "$b"
           else
           echo "$c"
           fi
       else
       echo "$a"
       fi

else
if [ $b -gt $c ]
   then
       if [ $a -gt $c ]
           then
           echo "$a"
           else
           echo "$c"
       fi
    else
    echo "$b"
    fi
fi