SquareString.cpp

#include<bits/stdc++.h>
using namespace std;
#define fer(i,a,b) for(re i = a; i<b; ++i)
#define re register int
#define pb push_back
#define ll long long
#define mod 1000000007
using namespace std;
typedef vector<int> vi;
typedef pair<int,int> pi;

 
int main ()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif
    ll tc;
    cin>>tc;
    while(tc--)
    {
        string s;
        cin>>s;
        int n=s.size();
        if(n%2==0){
            string s1=s.substr(0,n/2);
            string s2=s.substr(n/2,n-1);
            if(s1==s2) cout<<"YES"<<endl;
            else cout<<"NO"<<endl;
        }
        else{
            cout<<"NO"<<endl;
        }
    }
  return 0;
}