/******************************************************************************

                              Online C++ Compiler.
               Code, Compile, Run and Debug C++ program online.
Write your code in this editor and press "Run" button to compile and execute it.

*******************************************************************************/

#include <iostream>
#include <string>
using namespace std;

int main()
{
    string  s[4];
    int f=0,i,j;
    
     for(i=0;i<3;i++)
    {
        cin>>s[i];
    }
    for(i=0;i<2;i++)
    {
   
        
        for(j=0;j<2;j++)
            if(s[i][j]==s[i][j+1]){
                
               
                f=1;
            }
            if(s[i][j]==s[i+1][j])
            {
            
            
                f=1;
            }
        
    }
    if(f)
        cout<<"No"<<endl;
    else cout << "Yes" << endl;

    return 0;
}