#include <bits/stdc++.h>
using namespace std;
inline int read() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch > '9' || ch < '0') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = (x << 1) + (x << 3) + (ch ^ 48);
    ch = getchar();
  }
  return x * f;
}
int main() {
  char a[9];
  for (int i = 0; i < 9; i++) cin >> a[i];
  for (int i = 0; i < 9; i++)
    if (a[i] != a[8 - i]) {
      printf("NO");
      return 0;
    }
  printf("YES");
  return 0;
}
