#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); ++i)

int main() {
  vector Grid(3, vector<char>(3));
  rep(i, 3) rep(j, 3) cin >> Grid[i][j];
  char c = Grid[1][1];
  bool ok = true;
  ok &= Grid[0][0] == c;
  ok &= Grid[0][1] != c;
  ok &= Grid[0][2] == c;
  ok &= Grid[1][0] != c;
  ok &= Grid[1][1] == c;
  ok &= Grid[1][2] != c;
  ok &= Grid[2][0] == c;
  ok &= Grid[2][1] != c;
  ok &= Grid[2][2] == c;
  cout << (ok ? "Yes" : "No") << endl;
  return 0;
}