import java.util.Scanner;
import java.util.Arrays;
public class Main{
    public static void main(String[] args){
        Scanner sc = 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] = sc.nextInt();
            }
        }
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i = 0;i <= 100;i++){
            a[0] = i;
            for(int j = 0;j < 2;j++){
                b[j] = c[0][j] - a[0];
            }
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(infomation(a,b,c)){
                System.out.println("Yes");
                return;
            }
        }
        System.out.println("No");
    }
    public static boolean infomation(int[] a,int[] b,int[][] c){
        for(int i = 0;i < 3;i++){
            for(int j = 0;j < 3;j++){
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            }
        }
        return true;
    }
} import java.util.Scanner; Scanner java.util import java.util.Arrays; Arrays java.util public class Main{
    public static void main(String[] args){
        Scanner sc = 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] = sc.nextInt();
            }
        }
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i = 0;i <= 100;i++){
            a[0] = i;
            for(int j = 0;j < 2;j++){
                b[j] = c[0][j] - a[0];
            }
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(infomation(a,b,c)){
                System.out.println("Yes");
                return;
            }
        }
        System.out.println("No");
    }
    public static boolean infomation(int[] a,int[] b,int[][] c){
        for(int i = 0;i < 3;i++){
            for(int j = 0;j < 3;j++){
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            }
        }
        return true;
    }
} Main public static void main(String[] args){
        Scanner sc = 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] = sc.nextInt();
            }
        }
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i = 0;i <= 100;i++){
            a[0] = i;
            for(int j = 0;j < 2;j++){
                b[j] = c[0][j] - a[0];
            }
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(infomation(a,b,c)){
                System.out.println("Yes");
                return;
            }
        }
        System.out.println("No");
    } main {
        Scanner sc = 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] = sc.nextInt();
            }
        }
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i = 0;i <= 100;i++){
            a[0] = i;
            for(int j = 0;j < 2;j++){
                b[j] = c[0][j] - a[0];
            }
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(infomation(a,b,c)){
                System.out.println("Yes");
                return;
            }
        }
        System.out.println("No");
    } Scanner sc = new Scanner(System.in); sc 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] = 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 int[] a = new int[3]; a new int[3] 3 int[] b = new int[3]; b new int[3] 3 for(int i = 0;i <= 100;i++){
            a[0] = i;
            for(int j = 0;j < 2;j++){
                b[j] = c[0][j] - a[0];
            }
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(infomation(a,b,c)){
                System.out.println("Yes");
                return;
            }
        } int i = 0; int i = 0; i 0 i <= 100 i 100 i++ i++ i {
            a[0] = i;
            for(int j = 0;j < 2;j++){
                b[j] = c[0][j] - a[0];
            }
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(infomation(a,b,c)){
                System.out.println("Yes");
                return;
            }
        } {
            a[0] = i;
            for(int j = 0;j < 2;j++){
                b[j] = c[0][j] - a[0];
            }
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(infomation(a,b,c)){
                System.out.println("Yes");
                return;
            }
        } a[0] = i a[0] a 0 i for(int j = 0;j < 2;j++){
                b[j] = c[0][j] - a[0];
            } int j = 0; int j = 0; j 0 j < 2 j 2 j++ j++ j {
                b[j] = c[0][j] - a[0];
            } {
                b[j] = c[0][j] - a[0];
            } b[j] = c[0][j] - a[0] b[j] b j c[0][j] - a[0] c[0][j] c[0] c 0 j a[0] a 0 a[1] = c[1][0] - b[0] a[1] a 1 c[1][0] - b[0] c[1][0] c[1] c 1 0 b[0] b 0 a[2] = c[2][0] - b[0] a[2] a 2 c[2][0] - b[0] c[2][0] c[2] c 2 0 b[0] b 0 if(infomation(a,b,c)){
                System.out.println("Yes");
                return;
            } infomation(a,b,c) infomation a b c {
                System.out.println("Yes");
                return;
            } System.out.println("Yes") System.out.println System.out System System.out "Yes" return; System.out.println("No") System.out.println System.out System System.out "No" String[] args args public static boolean infomation(int[] a,int[] b,int[][] c){
        for(int i = 0;i < 3;i++){
            for(int j = 0;j < 3;j++){
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            }
        }
        return true;
    } infomation {
        for(int i = 0;i < 3;i++){
            for(int j = 0;j < 3;j++){
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            }
        }
        return true;
    } for(int i = 0;i < 3;i++){
            for(int j = 0;j < 3;j++){
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            }
        } int i = 0; int i = 0; i 0 i < 3 i 3 i++ i++ i {
            for(int j = 0;j < 3;j++){
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            }
        } {
            for(int j = 0;j < 3;j++){
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            }
        } for(int j = 0;j < 3;j++){
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            } int j = 0; int j = 0; j 0 j < 3 j 3 j++ j++ j {
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            } {
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            } if(a[i] + b[j] != c[i][j]){
                    return false;
                } a[i] + b[j] != c[i][j] a[i] + b[j] a[i] a i b[j] b j c[i][j] c[i] c i j {
                    return false;
                } return false; false return true; true int[] a a int[] b b int[][] c c public class Main{
    public static void main(String[] args){
        Scanner sc = 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] = sc.nextInt();
            }
        }
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i = 0;i <= 100;i++){
            a[0] = i;
            for(int j = 0;j < 2;j++){
                b[j] = c[0][j] - a[0];
            }
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(infomation(a,b,c)){
                System.out.println("Yes");
                return;
            }
        }
        System.out.println("No");
    }
    public static boolean infomation(int[] a,int[] b,int[][] c){
        for(int i = 0;i < 3;i++){
            for(int j = 0;j < 3;j++){
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            }
        }
        return true;
    }
} public class Main{
    public static void main(String[] args){
        Scanner sc = 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] = sc.nextInt();
            }
        }
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i = 0;i <= 100;i++){
            a[0] = i;
            for(int j = 0;j < 2;j++){
                b[j] = c[0][j] - a[0];
            }
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(infomation(a,b,c)){
                System.out.println("Yes");
                return;
            }
        }
        System.out.println("No");
    }
    public static boolean infomation(int[] a,int[] b,int[][] c){
        for(int i = 0;i < 3;i++){
            for(int j = 0;j < 3;j++){
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            }
        }
        return true;
    }
} Main
import java.util.Scanner;
import java.util.Arrays;
public class Main{
    public static void main(String[] args){
        Scanner sc = 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] = sc.nextInt();
            }
        }
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i = 0;i <= 100;i++){
            a[0] = i;
            for(int j = 0;j < 2;j++){
                b[j] = c[0][j] - a[0];
            }
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(infomation(a,b,c)){
                System.out.println("Yes");
                return;
            }
        }
        System.out.println("No");
    }
    public static boolean infomation(int[] a,int[] b,int[][] c){
        for(int i = 0;i < 3;i++){
            for(int j = 0;j < 3;j++){
                if(a[i] + b[j] != c[i][j]){
                    return false;
                }
            }
        }
        return true;
    }
}
