# https://atcoder.jp/contests/abc159/tasks/abc159_b
read S
n=$((${#S}))
a=$(((n-1)/2 - 1))
b=$(((n+3)/2 - 1))
l=$((a+1))
before=${S:0:a+1}
after=${S:b:l}
revbefore=`echo $before | rev`
revafter=`echo $after | rev`
echo $before >&2
echo $revbefore >&2
echo $after >&2
echo $revafter >&2
if [ $after == $revafter ] && [ $before == $revbefore ] ; then
  echo "Yes"
else
  echo "No"
fi
