#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;
typedef long long int ll;
typedef long double ld;
#define FOR(i,l,r) for(ll i=l;i<r;i++)
#define REP(i,n) FOR(i,0,n)
#define RFOR(i,l,r) for(ll i=r-1;i>=l;i--)
#define RREP(i,n) RFOR(i,0,n)
#define ALL(x) x.begin(),x.end()
#define PA pair<ll,ll>
#define F first
#define S second
#define BS(A,x) binary_search(ALL(A),x)
#define LB(A,x) (ll)(lower_bound(ALL(A),x)-A.begin())
#define UB(A,x) (ll)(upper_bound(ALL(A),x)-A.begin())
#define COU(A,x) (UB(A,x)-LB(A,x))
#define sz(c) ((ll)(c).size())
//#include<boost/multiprecision/cpp_int.hpp>
//namespace mp=boost::multiprecision;
//using Bint=mp::cpp_int;
template<typename T>using min_priority_queue=priority_queue<T,vector<T>,greater<T>>;
template<class T>bool chmax(T&a,T b){if(a<b){a=b;return 1;}return 0;}
template<class T>bool chmin(T&a,T b){if(b<a){a=b;return 1;}return 0;}
template<class T>void print(vector<T>A){REP(i,A.size()){if(i)cout<<" ";cout<<A[i];}cout<<endl;}
ld dist(ld x1,ld y1,ld x2,ld y2){return sqrtl((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));}
//using mint=modint1000000007;
using mint=modint998244353;
//const ll mod=1000000007;
const ll mod=998244353;
//using mint=modint;
int main(){
  string S[3];
  REP(i,3)cin>>S[i];
  REP(i,2)REP(j,3)if(S[i][j]==S[i+1][j]){cout<<"No"<<endl;return 0;}
  REP(i,3)REP(j,2)if(S[i][j]==S[i][j+1]){cout<<"No"<<endl;return 0;}
  cout<<"Yes"<<endl;return 0;
  return 0;
}