#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
using namespace std;

using ll = long long;
const int INF = 1e9;
const ll inf = 1LL<<60;

void solve() {
  vector<string> s(3);
  cin >> s[0] >> s[1] >> s[2];
  vector<int> dx = {1, 0, -1, 0}, dy = {0, 1, 0, -1};
  for (int i=0; i<3; i++) for (int j=0; j<3; j++) {
    for (int k=0; k<4; k++) {
      int nx = i + dx[k], ny = j + dy[k];
      if (0 <= nx && nx < 3 && 0 <= ny && ny < 3) {
        if (s[i][j] == s[nx][ny]) {
          cout << "No" << '\n';
          return;
        }
      }
    }
  }
  cout << "Yes" << '\n';
}

int main() {
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  // int t; cin >> t;
  /*while (t--)*/ solve();
}