#include <bits/stdc++.h>
using namespace std;
int main() {
  char a, b, c, d, e, f, g, h, i;
  cin >> a >> b >> c >> d >> e >> f >> g >> h >> i;
  if (a == i && b == h && c == g && d == f) {
    cout << "YES" << endl;
  } else {
    cout << "NO" << endl;
  }
  return 0;
}
