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[] total = new int[6];
    total[0] = c[0][0] + c[1][1] + c[2][2];
    total[1] = c[0][0] + c[1][2] + c[2][1];
    total[2] = c[0][1] + c[1][0] + c[2][2];
    total[3] = c[0][1] + c[2][0] + c[1][2];
    total[4] = c[0][2] + c[1][1] + c[2][0];
    total[5] = c[0][2] + c[1][0] + c[2][1];
    if (total[0] == total[1] && total[1] == total[2] && total[2] == total[3]
    && total[3] == total[4] && total[4] == total[5]){
      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[] total = new int[6];
    total[0] = c[0][0] + c[1][1] + c[2][2];
    total[1] = c[0][0] + c[1][2] + c[2][1];
    total[2] = c[0][1] + c[1][0] + c[2][2];
    total[3] = c[0][1] + c[2][0] + c[1][2];
    total[4] = c[0][2] + c[1][1] + c[2][0];
    total[5] = c[0][2] + c[1][0] + c[2][1];
    if (total[0] == total[1] && total[1] == total[2] && total[2] == total[3]
    && total[3] == total[4] && total[4] == total[5]){
      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[] total = new int[6];
    total[0] = c[0][0] + c[1][1] + c[2][2];
    total[1] = c[0][0] + c[1][2] + c[2][1];
    total[2] = c[0][1] + c[1][0] + c[2][2];
    total[3] = c[0][1] + c[2][0] + c[1][2];
    total[4] = c[0][2] + c[1][1] + c[2][0];
    total[5] = c[0][2] + c[1][0] + c[2][1];
    if (total[0] == total[1] && total[1] == total[2] && total[2] == total[3]
    && total[3] == total[4] && total[4] == total[5]){
      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[] total = new int[6];
    total[0] = c[0][0] + c[1][1] + c[2][2];
    total[1] = c[0][0] + c[1][2] + c[2][1];
    total[2] = c[0][1] + c[1][0] + c[2][2];
    total[3] = c[0][1] + c[2][0] + c[1][2];
    total[4] = c[0][2] + c[1][1] + c[2][0];
    total[5] = c[0][2] + c[1][0] + c[2][1];
    if (total[0] == total[1] && total[1] == total[2] && total[2] == total[3]
    && total[3] == total[4] && total[4] == total[5]){
      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[] total = new int[6]; total new int[6] 6 total[0] = c[0][0] + c[1][1] + c[2][2] total[0] total 0 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 total[1] = c[0][0] + c[1][2] + c[2][1] total[1] total 1 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 total[2] = c[0][1] + c[1][0] + c[2][2] total[2] total 2 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 total[3] = c[0][1] + c[2][0] + c[1][2] total[3] total 3 c[0][1] + c[2][0] + c[1][2] c[0][1] + c[2][0] + c[1][2] c[0][1] c[0] c 0 1 c[2][0] c[2] c 2 0 c[1][2] c[1] c 1 2 total[4] = c[0][2] + c[1][1] + c[2][0] total[4] total 4 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 total[5] = c[0][2] + c[1][0] + c[2][1] total[5] total 5 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 (total[0] == total[1] && total[1] == total[2] && total[2] == total[3]
    && total[3] == total[4] && total[4] == total[5]){
      System.out.println("Yes");
    } else {System.out.println("No");} total[0] == total[1] && total[1] == total[2] && total[2] == total[3]
    && total[3] == total[4] && total[4] == total[5] total[3] == total[4] total[2] == total[3] total[0] == total[1] && total[1] == total[2] && total[2] == total[3]
    && total[3] == total[4] && total[4] == total[5] total[0] == total[1] total[0] total 0 total[1] total 1 total[1] == total[2] total[1] total 1 total[2] total 2 total[2] == total[3] total[2] total 2 total[3] total 3 total[3] == total[4] total[3] total 3 total[4] total 4 total[4] == total[5] total[4] total 4 total[5] total 5 {
      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[] total = new int[6];
    total[0] = c[0][0] + c[1][1] + c[2][2];
    total[1] = c[0][0] + c[1][2] + c[2][1];
    total[2] = c[0][1] + c[1][0] + c[2][2];
    total[3] = c[0][1] + c[2][0] + c[1][2];
    total[4] = c[0][2] + c[1][1] + c[2][0];
    total[5] = c[0][2] + c[1][0] + c[2][1];
    if (total[0] == total[1] && total[1] == total[2] && total[2] == total[3]
    && total[3] == total[4] && total[4] == total[5]){
      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[] total = new int[6];
    total[0] = c[0][0] + c[1][1] + c[2][2];
    total[1] = c[0][0] + c[1][2] + c[2][1];
    total[2] = c[0][1] + c[1][0] + c[2][2];
    total[3] = c[0][1] + c[2][0] + c[1][2];
    total[4] = c[0][2] + c[1][1] + c[2][0];
    total[5] = c[0][2] + c[1][0] + c[2][1];
    if (total[0] == total[1] && total[1] == total[2] && total[2] == total[3]
    && total[3] == total[4] && total[4] == total[5]){
      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[] total = new int[6];
    total[0] = c[0][0] + c[1][1] + c[2][2];
    total[1] = c[0][0] + c[1][2] + c[2][1];
    total[2] = c[0][1] + c[1][0] + c[2][2];
    total[3] = c[0][1] + c[2][0] + c[1][2];
    total[4] = c[0][2] + c[1][1] + c[2][0];
    total[5] = c[0][2] + c[1][0] + c[2][1];
    if (total[0] == total[1] && total[1] == total[2] && total[2] == total[3]
    && total[3] == total[4] && total[4] == total[5]){
      System.out.println("Yes");
    } else {System.out.println("No");}
    }
}
