#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
#include <queue>
#include <map>
#include <cmath>
#include <iomanip>
#include <set>
#include <cstdio>
#include <string>

using namespace std;

const int dx[] = {0,0,-1,1};
const int dy[] = {-1,1,0,0};

int main() {
  vector<string> s(3);
  for (int i = 0; i < 3; i++) {
    cin >> s[i];
  }
  bool ok = true;
  for (int i = 0; i < 3; i++) {
    for (int j = 0; j < 3; j++) {
      for (int k = 0; k < 4; k++) {
        int ny = i + dx[k];
        int nx = j + dy[k];
        if (nx < 0 || ny < 0 || nx >= 3 || ny >= 3) {
          continue;
        }
        ok &= (s[i][j] != s[ny][nx]);
      }
    }
  }
  cout << (ok? "Yes" : "No") << endl;
  return 0; 
}