import java.util.Scanner;

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] = Integer.parseInt(sc.next());
            }
        }
        int[] t = new int[6] ;
        t[0] = c[0][0] + c[1][1] + c[2][2];
        t[1] = c[0][1] + c[1][2] + c[2][0];
        t[2] = c[0][2] + c[1][0] + c[2][1];
        t[3] = c[0][2] + c[1][1] + c[2][0];
        t[4] = c[0][1] + c[1][0] + c[2][2];
        t[5] = c[0][0] + c[2][1] + c[1][2];
        
        String ans = "Yes";
        for(int i = 1;i<6;i++){
            if(t[i] != t[0]){
                ans = "No";
                break;
            }
        }
        System.out.println(ans);
    }
    
} import java.util.Scanner; Scanner 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] = Integer.parseInt(sc.next());
            }
        }
        int[] t = new int[6] ;
        t[0] = c[0][0] + c[1][1] + c[2][2];
        t[1] = c[0][1] + c[1][2] + c[2][0];
        t[2] = c[0][2] + c[1][0] + c[2][1];
        t[3] = c[0][2] + c[1][1] + c[2][0];
        t[4] = c[0][1] + c[1][0] + c[2][2];
        t[5] = c[0][0] + c[2][1] + c[1][2];
        
        String ans = "Yes";
        for(int i = 1;i<6;i++){
            if(t[i] != t[0]){
                ans = "No";
                break;
            }
        }
        System.out.println(ans);
    }
    
} 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] = Integer.parseInt(sc.next());
            }
        }
        int[] t = new int[6] ;
        t[0] = c[0][0] + c[1][1] + c[2][2];
        t[1] = c[0][1] + c[1][2] + c[2][0];
        t[2] = c[0][2] + c[1][0] + c[2][1];
        t[3] = c[0][2] + c[1][1] + c[2][0];
        t[4] = c[0][1] + c[1][0] + c[2][2];
        t[5] = c[0][0] + c[2][1] + c[1][2];
        
        String ans = "Yes";
        for(int i = 1;i<6;i++){
            if(t[i] != t[0]){
                ans = "No";
                break;
            }
        }
        System.out.println(ans);
    } 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] = Integer.parseInt(sc.next());
            }
        }
        int[] t = new int[6] ;
        t[0] = c[0][0] + c[1][1] + c[2][2];
        t[1] = c[0][1] + c[1][2] + c[2][0];
        t[2] = c[0][2] + c[1][0] + c[2][1];
        t[3] = c[0][2] + c[1][1] + c[2][0];
        t[4] = c[0][1] + c[1][0] + c[2][2];
        t[5] = c[0][0] + c[2][1] + c[1][2];
        
        String ans = "Yes";
        for(int i = 1;i<6;i++){
            if(t[i] != t[0]){
                ans = "No";
                break;
            }
        }
        System.out.println(ans);
    } 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] = Integer.parseInt(sc.next());
            }
        } 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] = Integer.parseInt(sc.next());
            }
        } {
            for(int j=0;j<3;j++){
                c[i][j] = Integer.parseInt(sc.next());
            }
        } for(int j=0;j<3;j++){
                c[i][j] = Integer.parseInt(sc.next());
            } int j=0; int j=0; j 0 j<3 j 3 j++ j++ j {
                c[i][j] = Integer.parseInt(sc.next());
            } {
                c[i][j] = Integer.parseInt(sc.next());
            } c[i][j] = Integer.parseInt(sc.next()) c[i][j] c[i] c i j Integer.parseInt(sc.next()) Integer.parseInt Integer sc.next() sc.next sc int[] t = new int[6] ; t new int[6] 6 t[0] = c[0][0] + c[1][1] + c[2][2] t[0] t 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 t[1] = c[0][1] + c[1][2] + c[2][0] t[1] t 1 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 t[2] = c[0][2] + c[1][0] + c[2][1] t[2] t 2 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 t[3] = c[0][2] + c[1][1] + c[2][0] t[3] t 3 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 t[4] = c[0][1] + c[1][0] + c[2][2] t[4] t 4 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 t[5] = c[0][0] + c[2][1] + c[1][2] t[5] t 5 c[0][0] + c[2][1] + c[1][2] c[0][0] + c[2][1] + c[1][2] c[0][0] c[0] c 0 0 c[2][1] c[2] c 2 1 c[1][2] c[1] c 1 2 String ans = "Yes"; ans "Yes" for(int i = 1;i<6;i++){
            if(t[i] != t[0]){
                ans = "No";
                break;
            }
        } int i = 1; int i = 1; i 1 i<6 i 6 i++ i++ i {
            if(t[i] != t[0]){
                ans = "No";
                break;
            }
        } {
            if(t[i] != t[0]){
                ans = "No";
                break;
            }
        } if(t[i] != t[0]){
                ans = "No";
                break;
            } t[i] != t[0] t[i] t i t[0] t 0 {
                ans = "No";
                break;
            } ans = "No" ans "No" break; System.out.println(ans) System.out.println System.out System System.out ans String[] args args 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] = Integer.parseInt(sc.next());
            }
        }
        int[] t = new int[6] ;
        t[0] = c[0][0] + c[1][1] + c[2][2];
        t[1] = c[0][1] + c[1][2] + c[2][0];
        t[2] = c[0][2] + c[1][0] + c[2][1];
        t[3] = c[0][2] + c[1][1] + c[2][0];
        t[4] = c[0][1] + c[1][0] + c[2][2];
        t[5] = c[0][0] + c[2][1] + c[1][2];
        
        String ans = "Yes";
        for(int i = 1;i<6;i++){
            if(t[i] != t[0]){
                ans = "No";
                break;
            }
        }
        System.out.println(ans);
    }
    
} 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] = Integer.parseInt(sc.next());
            }
        }
        int[] t = new int[6] ;
        t[0] = c[0][0] + c[1][1] + c[2][2];
        t[1] = c[0][1] + c[1][2] + c[2][0];
        t[2] = c[0][2] + c[1][0] + c[2][1];
        t[3] = c[0][2] + c[1][1] + c[2][0];
        t[4] = c[0][1] + c[1][0] + c[2][2];
        t[5] = c[0][0] + c[2][1] + c[1][2];
        
        String ans = "Yes";
        for(int i = 1;i<6;i++){
            if(t[i] != t[0]){
                ans = "No";
                break;
            }
        }
        System.out.println(ans);
    }
    
} Main
import java.util.Scanner;

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] = Integer.parseInt(sc.next());
            }
        }
        int[] t = new int[6] ;
        t[0] = c[0][0] + c[1][1] + c[2][2];
        t[1] = c[0][1] + c[1][2] + c[2][0];
        t[2] = c[0][2] + c[1][0] + c[2][1];
        t[3] = c[0][2] + c[1][1] + c[2][0];
        t[4] = c[0][1] + c[1][0] + c[2][2];
        t[5] = c[0][0] + c[2][1] + c[1][2];
        
        String ans = "Yes";
        for(int i = 1;i<6;i++){
            if(t[i] != t[0]){
                ans = "No";
                break;
            }
        }
        System.out.println(ans);
    }
    
}