import std.conv, std.stdio;
import std.algorithm, std.array, std.string, std.range;
void main()
{
    auto s = readln.chomp.to!dstring;
    if (s[0..$/2].isPalindrome && (s[0..$/2] == s[$/2+1..$]))
        "Yes".writeln;
    else
        "No".writeln;
}

auto isPalindrome(T)(in T[] a)
{
    return a.equal(a.retro);
}
