#include <bits/stdc++.h>
#define be(v) (v).begin(),(v).end()
#define pb(q) push_back(q)
#define rep(i, n) for(int i=0;i<n;i++)
#define all(i, v) for(auto& i : v)
typedef long long ll;
using namespace std;
const ll mod=1000000007, INF=(1LL<<60);
#define doublecout(a) cout<<fixed<<setprecision(10)<<a<<endl;

int main() {
    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(false); 
    string s[3];
    rep(i, 3) cin >> s[i];
    bool f = true;
    rep(i, 3) rep(j, 2) {
        if(s[i][j] == s[i][j + 1]) f = false;
        if(s[j][i] == s[j + 1][i]) f = false;
    }
    cout << (f ? "Yes" : "No") << endl;
    return 0;
}