import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int[][] c = new int[3][3];
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                c[i][j] = sc.nextInt();
            }
        }

        boolean flag = false;
        for (int x = 0; x <= 100; x++) {
            int a1 = c[0][0] - x;
            int a2 = c[0][1] - x;
            int a3 = c[0][2] - x;
            int b1 = x;
            int b2 = c[1][0] - a1;
            int b3 = c[2][0] - a1;

            if (c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3) {
                flag = true;
                break;
            }
        }

        if (flag) {
            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) {
        int[][] c = new int[3][3];
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                c[i][j] = sc.nextInt();
            }
        }

        boolean flag = false;
        for (int x = 0; x <= 100; x++) {
            int a1 = c[0][0] - x;
            int a2 = c[0][1] - x;
            int a3 = c[0][2] - x;
            int b1 = x;
            int b2 = c[1][0] - a1;
            int b3 = c[2][0] - a1;

            if (c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3) {
                flag = true;
                break;
            }
        }

        if (flag) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
} Main public static void main(String[] args) {
        int[][] c = new int[3][3];
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                c[i][j] = sc.nextInt();
            }
        }

        boolean flag = false;
        for (int x = 0; x <= 100; x++) {
            int a1 = c[0][0] - x;
            int a2 = c[0][1] - x;
            int a3 = c[0][2] - x;
            int b1 = x;
            int b2 = c[1][0] - a1;
            int b3 = c[2][0] - a1;

            if (c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3) {
                flag = true;
                break;
            }
        }

        if (flag) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    } main {
        int[][] c = new int[3][3];
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                c[i][j] = sc.nextInt();
            }
        }

        boolean flag = false;
        for (int x = 0; x <= 100; x++) {
            int a1 = c[0][0] - x;
            int a2 = c[0][1] - x;
            int a3 = c[0][2] - x;
            int b1 = x;
            int b2 = c[1][0] - a1;
            int b3 = c[2][0] - a1;

            if (c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3) {
                flag = true;
                break;
            }
        }

        if (flag) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    } int[][] c = new int[3][3]; c new int[3][3] 3 3 Scanner sc = new Scanner(System.in); sc new Scanner(System.in) for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                c[i][j] = sc.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] = sc.nextInt();
            }
        } {
            for (int j = 0; j < 3; j++) {
                c[i][j] = sc.nextInt();
            }
        } for (int j = 0; j < 3; j++) {
                c[i][j] = sc.nextInt();
            } int j = 0; int j = 0; j 0 j < 3 j 3 j++ j++ j {
                c[i][j] = sc.nextInt();
            } {
                c[i][j] = sc.nextInt();
            } c[i][j] = sc.nextInt() c[i][j] c[i] c i j sc.nextInt() sc.nextInt sc boolean flag = false; flag false for (int x = 0; x <= 100; x++) {
            int a1 = c[0][0] - x;
            int a2 = c[0][1] - x;
            int a3 = c[0][2] - x;
            int b1 = x;
            int b2 = c[1][0] - a1;
            int b3 = c[2][0] - a1;

            if (c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3) {
                flag = true;
                break;
            }
        } int x = 0; int x = 0; x 0 x <= 100 x 100 x++ x++ x {
            int a1 = c[0][0] - x;
            int a2 = c[0][1] - x;
            int a3 = c[0][2] - x;
            int b1 = x;
            int b2 = c[1][0] - a1;
            int b3 = c[2][0] - a1;

            if (c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3) {
                flag = true;
                break;
            }
        } {
            int a1 = c[0][0] - x;
            int a2 = c[0][1] - x;
            int a3 = c[0][2] - x;
            int b1 = x;
            int b2 = c[1][0] - a1;
            int b3 = c[2][0] - a1;

            if (c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3) {
                flag = true;
                break;
            }
        } int a1 = c[0][0] - x; a1 c[0][0] - x c[0][0] c[0] c 0 0 x int a2 = c[0][1] - x; a2 c[0][1] - x c[0][1] c[0] c 0 1 x int a3 = c[0][2] - x; a3 c[0][2] - x c[0][2] c[0] c 0 2 x int b1 = x; b1 x int b2 = c[1][0] - a1; b2 c[1][0] - a1 c[1][0] c[1] c 1 0 a1 int b3 = c[2][0] - a1; b3 c[2][0] - a1 c[2][0] c[2] c 2 0 a1 if (c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3) {
                flag = true;
                break;
            } c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3 c[2][1] == a2+b3 c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3 c[1][1] == a2+b2 c[1][1] c[1] c 1 1 a2+b2 a2 b2 c[1][2] == a3+b2 c[1][2] c[1] c 1 2 a3+b2 a3 b2 c[2][1] == a2+b3 c[2][1] c[2] c 2 1 a2+b3 a2 b3 c[2][2] == a3+b3 c[2][2] c[2] c 2 2 a3+b3 a3 b3 {
                flag = true;
                break;
            } flag = true flag true break; if (flag) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        } flag {
            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) {
        int[][] c = new int[3][3];
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                c[i][j] = sc.nextInt();
            }
        }

        boolean flag = false;
        for (int x = 0; x <= 100; x++) {
            int a1 = c[0][0] - x;
            int a2 = c[0][1] - x;
            int a3 = c[0][2] - x;
            int b1 = x;
            int b2 = c[1][0] - a1;
            int b3 = c[2][0] - a1;

            if (c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3) {
                flag = true;
                break;
            }
        }

        if (flag) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
} public class Main {
    public static void main(String[] args) {
        int[][] c = new int[3][3];
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                c[i][j] = sc.nextInt();
            }
        }

        boolean flag = false;
        for (int x = 0; x <= 100; x++) {
            int a1 = c[0][0] - x;
            int a2 = c[0][1] - x;
            int a3 = c[0][2] - x;
            int b1 = x;
            int b2 = c[1][0] - a1;
            int b3 = c[2][0] - a1;

            if (c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3) {
                flag = true;
                break;
            }
        }

        if (flag) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int[][] c = new int[3][3];
        Scanner sc = new Scanner(System.in);
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                c[i][j] = sc.nextInt();
            }
        }

        boolean flag = false;
        for (int x = 0; x <= 100; x++) {
            int a1 = c[0][0] - x;
            int a2 = c[0][1] - x;
            int a3 = c[0][2] - x;
            int b1 = x;
            int b2 = c[1][0] - a1;
            int b3 = c[2][0] - a1;

            if (c[1][1] == a2+b2 && c[1][2] == a3+b2 && c[2][1] == a2+b3 && c[2][2] == a3+b3) {
                flag = true;
                break;
            }
        }

        if (flag) {
            System.out.println("Yes");
        } else {
            System.out.println("No");
        }
    }
}