#include <bits/stdc++.h>

#define long long long
#define Integer_MAX_VALUE 0x7fffffff
#define Integer_MIN_VALUE 0x80000000
#define Long_MAX_VALUE 0x7fffffffffffffffL
#define Long_MIN_VALUE 0x8000000000000000L

using namespace std;

struct Solution
{
    void run()
    {
        string s;
        cin >> s;
        int len = s.length();

        if (len % 2 != 0)
        {
            cout << "NO" << endl;
            return;
        }

        for (int i = 0; i < len / 2; i++)
        {
            if (s[i] != s[i + len / 2])
            {
                cout << "NO" << endl;
                return;
            }
        }
        cout << "YES" << endl;
    }
};

int main()
{
    ios_base::sync_with_stdio(false);

    Solution solution = Solution();

    int t;
    cin >> t;
    for (int i = 0; i < t; i++)
    {
        solution.run();
    }
    return 0;
}