TICKETS5

#include <bits/stdc++.h>
using namespace std;

int main() {
	// your code goes here
	int t;
	cin>>t;
	while(t--)
	{
	    string s;
	    cin>>s;
	    string s1="";
	    s1=s[0];
	    s1=s1+s[1];
	    bool flag=true;
	    for(int i=0;i<s.length();i++)
	    {
	        if(i%2==0)
	        {
	            if(s[i]!=s1[0])
	            {
	                flag=false;
	                break;
	            }
	        }
	        else
	        {
	            if(s[i]!=s1[1])
	            {
	                flag=false;
	                break;
	            }
	        }
	        if(i>0)
	        {
	            if(s[i]==s[i-1])
	            flag=false;
	        }
	    }
	    if(flag==true)
	    cout<<"YES"<<endl;
	    else
	    cout<<"NO"<<endl;
	}
	return 0;
}