import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    int[][] c = new int[3][3];
    for (int i = 0; i < 3; i++) {
      for (int j = 0; j < 3; j++) {
        c[i][j] = scanner.nextInt();
      }
    }

    int c012 = c[0][0] + c[1][1] + c[2][2];
    int c021 = c[0][0] + c[1][2] + c[2][1];
    int c102 = c[0][1] + c[1][0] + c[2][2];
    int c120 = c[0][1] + c[1][2] + c[2][0];
    int c210 = c[0][2] + c[1][1] + c[2][0];
    int c201 = c[0][2] + c[1][0] + c[2][1];

    if (c012 == c021 && c021 == c102 && c102 == c120 && c120 == c210 && c210 == c201) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  }
} import java.util.Scanner; Scanner java.util public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    int[][] c = new int[3][3];
    for (int i = 0; i < 3; i++) {
      for (int j = 0; j < 3; j++) {
        c[i][j] = scanner.nextInt();
      }
    }

    int c012 = c[0][0] + c[1][1] + c[2][2];
    int c021 = c[0][0] + c[1][2] + c[2][1];
    int c102 = c[0][1] + c[1][0] + c[2][2];
    int c120 = c[0][1] + c[1][2] + c[2][0];
    int c210 = c[0][2] + c[1][1] + c[2][0];
    int c201 = c[0][2] + c[1][0] + c[2][1];

    if (c012 == c021 && c021 == c102 && c102 == c120 && c120 == c210 && c210 == c201) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  }
} Main public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    int[][] c = new int[3][3];
    for (int i = 0; i < 3; i++) {
      for (int j = 0; j < 3; j++) {
        c[i][j] = scanner.nextInt();
      }
    }

    int c012 = c[0][0] + c[1][1] + c[2][2];
    int c021 = c[0][0] + c[1][2] + c[2][1];
    int c102 = c[0][1] + c[1][0] + c[2][2];
    int c120 = c[0][1] + c[1][2] + c[2][0];
    int c210 = c[0][2] + c[1][1] + c[2][0];
    int c201 = c[0][2] + c[1][0] + c[2][1];

    if (c012 == c021 && c021 == c102 && c102 == c120 && c120 == c210 && c210 == c201) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  } main {
    Scanner scanner = new Scanner(System.in);

    int[][] c = new int[3][3];
    for (int i = 0; i < 3; i++) {
      for (int j = 0; j < 3; j++) {
        c[i][j] = scanner.nextInt();
      }
    }

    int c012 = c[0][0] + c[1][1] + c[2][2];
    int c021 = c[0][0] + c[1][2] + c[2][1];
    int c102 = c[0][1] + c[1][0] + c[2][2];
    int c120 = c[0][1] + c[1][2] + c[2][0];
    int c210 = c[0][2] + c[1][1] + c[2][0];
    int c201 = c[0][2] + c[1][0] + c[2][1];

    if (c012 == c021 && c021 == c102 && c102 == c120 && c120 == c210 && c210 == c201) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) int[][] c = new int[3][3]; c new int[3][3] 3 3 for (int i = 0; i < 3; i++) {
      for (int j = 0; j < 3; j++) {
        c[i][j] = scanner.nextInt();
      }
    } int i = 0; int i = 0; i 0 i < 3 i 3 i++ i++ i {
      for (int j = 0; j < 3; j++) {
        c[i][j] = scanner.nextInt();
      }
    } {
      for (int j = 0; j < 3; j++) {
        c[i][j] = scanner.nextInt();
      }
    } for (int j = 0; j < 3; j++) {
        c[i][j] = scanner.nextInt();
      } int j = 0; int j = 0; j 0 j < 3 j 3 j++ j++ j {
        c[i][j] = scanner.nextInt();
      } {
        c[i][j] = scanner.nextInt();
      } c[i][j] = scanner.nextInt() c[i][j] c[i] c i j scanner.nextInt() scanner.nextInt scanner int c012 = c[0][0] + c[1][1] + c[2][2]; c012 c[0][0] + c[1][1] + c[2][2] c[0][0] + c[1][1] + c[2][2] c[0][0] c[0] c 0 0 c[1][1] c[1] c 1 1 c[2][2] c[2] c 2 2 int c021 = c[0][0] + c[1][2] + c[2][1]; c021 c[0][0] + c[1][2] + c[2][1] c[0][0] + c[1][2] + c[2][1] c[0][0] c[0] c 0 0 c[1][2] c[1] c 1 2 c[2][1] c[2] c 2 1 int c102 = c[0][1] + c[1][0] + c[2][2]; c102 c[0][1] + c[1][0] + c[2][2] c[0][1] + c[1][0] + c[2][2] c[0][1] c[0] c 0 1 c[1][0] c[1] c 1 0 c[2][2] c[2] c 2 2 int c120 = c[0][1] + c[1][2] + c[2][0]; c120 c[0][1] + c[1][2] + c[2][0] c[0][1] + c[1][2] + c[2][0] c[0][1] c[0] c 0 1 c[1][2] c[1] c 1 2 c[2][0] c[2] c 2 0 int c210 = c[0][2] + c[1][1] + c[2][0]; c210 c[0][2] + c[1][1] + c[2][0] c[0][2] + c[1][1] + c[2][0] c[0][2] c[0] c 0 2 c[1][1] c[1] c 1 1 c[2][0] c[2] c 2 0 int c201 = c[0][2] + c[1][0] + c[2][1]; c201 c[0][2] + c[1][0] + c[2][1] c[0][2] + c[1][0] + c[2][1] c[0][2] c[0] c 0 2 c[1][0] c[1] c 1 0 c[2][1] c[2] c 2 1 if (c012 == c021 && c021 == c102 && c102 == c120 && c120 == c210 && c210 == c201) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    } c012 == c021 && c021 == c102 && c102 == c120 && c120 == c210 && c210 == c201 c120 == c210 c102 == c120 c012 == c021 && c021 == c102 && c102 == c120 && c120 == c210 && c210 == c201 c012 == c021 c012 c021 c021 == c102 c021 c102 c102 == c120 c102 c120 c120 == c210 c120 c210 c210 == c201 c210 c201 {
      System.out.println("Yes");
    } System.out.println("Yes") System.out.println System.out System System.out "Yes" {
      System.out.println("No");
    } System.out.println("No") System.out.println System.out System System.out "No" String[] args args public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    int[][] c = new int[3][3];
    for (int i = 0; i < 3; i++) {
      for (int j = 0; j < 3; j++) {
        c[i][j] = scanner.nextInt();
      }
    }

    int c012 = c[0][0] + c[1][1] + c[2][2];
    int c021 = c[0][0] + c[1][2] + c[2][1];
    int c102 = c[0][1] + c[1][0] + c[2][2];
    int c120 = c[0][1] + c[1][2] + c[2][0];
    int c210 = c[0][2] + c[1][1] + c[2][0];
    int c201 = c[0][2] + c[1][0] + c[2][1];

    if (c012 == c021 && c021 == c102 && c102 == c120 && c120 == c210 && c210 == c201) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  }
} public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    int[][] c = new int[3][3];
    for (int i = 0; i < 3; i++) {
      for (int j = 0; j < 3; j++) {
        c[i][j] = scanner.nextInt();
      }
    }

    int c012 = c[0][0] + c[1][1] + c[2][2];
    int c021 = c[0][0] + c[1][2] + c[2][1];
    int c102 = c[0][1] + c[1][0] + c[2][2];
    int c120 = c[0][1] + c[1][2] + c[2][0];
    int c210 = c[0][2] + c[1][1] + c[2][0];
    int c201 = c[0][2] + c[1][0] + c[2][1];

    if (c012 == c021 && c021 == c102 && c102 == c120 && c120 == c210 && c210 == c201) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  }
} Main
import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    int[][] c = new int[3][3];
    for (int i = 0; i < 3; i++) {
      for (int j = 0; j < 3; j++) {
        c[i][j] = scanner.nextInt();
      }
    }

    int c012 = c[0][0] + c[1][1] + c[2][2];
    int c021 = c[0][0] + c[1][2] + c[2][1];
    int c102 = c[0][1] + c[1][0] + c[2][2];
    int c120 = c[0][1] + c[1][2] + c[2][0];
    int c210 = c[0][2] + c[1][1] + c[2][0];
    int c201 = c[0][2] + c[1][0] + c[2][1];

    if (c012 == c021 && c021 == c102 && c102 == c120 && c120 == c210 && c210 == c201) {
      System.out.println("Yes");
    } else {
      System.out.println("No");
    }
  }
}
