#include <iostream>
#include <vector>
#include <string>

#define rep(i,n) for(i=0; i<n; ++i)
#define in(a) cin >> a
#define out(a,b) cout << a << b
using namespace std;
using lint = long long;

int main(void){
    int i, j, k, n, m, cnt = 0;
    vector<string> s(3);
    bool f=true;
    rep(i,3)    in(s[i]);
    rep(i,3){
        rep(j,2){
            if(s[i][j]==s[i][j+1])  f=false;

        }
    }
        rep(i,3){
        rep(j,2){
            if(s[j][i]==s[j+1][i])  f=false;

        }
    }
    if(f)   out("Yes",endl);
    else    out("No",endl);
    return 0;
}