import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int[][] c = new int[3][3];
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i=0; i<3; i++) {
            for(int j=0; j<3; j++) {
                c[i][j] = Integer.parseInt(sc.next());
            }
        }
        String ans = "No";
        for(int i=0; i<=100; i++) {
            a[0] = i;
            b[0] = c[0][0] - i;
            b[1] = c[0][1] - i;
            b[2] = c[0][2] - i;
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2]) {
                ans = "Yes";
                break;
            }
        }
        
        System.out.println(ans);
        
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int[][] c = new int[3][3];
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i=0; i<3; i++) {
            for(int j=0; j<3; j++) {
                c[i][j] = Integer.parseInt(sc.next());
            }
        }
        String ans = "No";
        for(int i=0; i<=100; i++) {
            a[0] = i;
            b[0] = c[0][0] - i;
            b[1] = c[0][1] - i;
            b[2] = c[0][2] - i;
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2]) {
                ans = "Yes";
                break;
            }
        }
        
        System.out.println(ans);
        
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int[][] c = new int[3][3];
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i=0; i<3; i++) {
            for(int j=0; j<3; j++) {
                c[i][j] = Integer.parseInt(sc.next());
            }
        }
        String ans = "No";
        for(int i=0; i<=100; i++) {
            a[0] = i;
            b[0] = c[0][0] - i;
            b[1] = c[0][1] - i;
            b[2] = c[0][2] - i;
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2]) {
                ans = "Yes";
                break;
            }
        }
        
        System.out.println(ans);
        
    } main {
        Scanner sc = new Scanner(System.in);
        int[][] c = new int[3][3];
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i=0; i<3; i++) {
            for(int j=0; j<3; j++) {
                c[i][j] = Integer.parseInt(sc.next());
            }
        }
        String ans = "No";
        for(int i=0; i<=100; i++) {
            a[0] = i;
            b[0] = c[0][0] - i;
            b[1] = c[0][1] - i;
            b[2] = c[0][2] - i;
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2]) {
                ans = "Yes";
                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 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<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 String ans = "No"; ans "No" for(int i=0; i<=100; i++) {
            a[0] = i;
            b[0] = c[0][0] - i;
            b[1] = c[0][1] - i;
            b[2] = c[0][2] - i;
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2]) {
                ans = "Yes";
                break;
            }
        } int i=0; int i=0; i 0 i<=100 i 100 i++ i++ i {
            a[0] = i;
            b[0] = c[0][0] - i;
            b[1] = c[0][1] - i;
            b[2] = c[0][2] - i;
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2]) {
                ans = "Yes";
                break;
            }
        } {
            a[0] = i;
            b[0] = c[0][0] - i;
            b[1] = c[0][1] - i;
            b[2] = c[0][2] - i;
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2]) {
                ans = "Yes";
                break;
            }
        } a[0] = i a[0] a 0 i b[0] = c[0][0] - i b[0] b 0 c[0][0] - i c[0][0] c[0] c 0 0 i b[1] = c[0][1] - i b[1] b 1 c[0][1] - i c[0][1] c[0] c 0 1 i b[2] = c[0][2] - i b[2] b 2 c[0][2] - i c[0][2] c[0] c 0 2 i 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(c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2]) {
                ans = "Yes";
                break;
            } c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2] c[2][1] == a[2]+b[1] c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2] c[1][1] == a[1]+b[1] c[1][1] c[1] c 1 1 a[1]+b[1] a[1] a 1 b[1] b 1 c[1][2] == a[1]+b[2] c[1][2] c[1] c 1 2 a[1]+b[2] a[1] a 1 b[2] b 2 c[2][1] == a[2]+b[1] c[2][1] c[2] c 2 1 a[2]+b[1] a[2] a 2 b[1] b 1 c[2][2] == a[2]+b[2] c[2][2] c[2] c 2 2 a[2]+b[2] a[2] a 2 b[2] b 2 {
                ans = "Yes";
                break;
            } ans = "Yes" ans "Yes" 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];
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i=0; i<3; i++) {
            for(int j=0; j<3; j++) {
                c[i][j] = Integer.parseInt(sc.next());
            }
        }
        String ans = "No";
        for(int i=0; i<=100; i++) {
            a[0] = i;
            b[0] = c[0][0] - i;
            b[1] = c[0][1] - i;
            b[2] = c[0][2] - i;
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2]) {
                ans = "Yes";
                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];
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i=0; i<3; i++) {
            for(int j=0; j<3; j++) {
                c[i][j] = Integer.parseInt(sc.next());
            }
        }
        String ans = "No";
        for(int i=0; i<=100; i++) {
            a[0] = i;
            b[0] = c[0][0] - i;
            b[1] = c[0][1] - i;
            b[2] = c[0][2] - i;
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2]) {
                ans = "Yes";
                break;
            }
        }
        
        System.out.println(ans);
        
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int[][] c = new int[3][3];
        int[] a = new int[3];
        int[] b = new int[3];
        for(int i=0; i<3; i++) {
            for(int j=0; j<3; j++) {
                c[i][j] = Integer.parseInt(sc.next());
            }
        }
        String ans = "No";
        for(int i=0; i<=100; i++) {
            a[0] = i;
            b[0] = c[0][0] - i;
            b[1] = c[0][1] - i;
            b[2] = c[0][2] - i;
            a[1] = c[1][0] - b[0];
            a[2] = c[2][0] - b[0];
            if(c[1][1] == a[1]+b[1] && c[1][2] == a[1]+b[2] && c[2][1] == a[2]+b[1] && c[2][2] == a[2]+b[2]) {
                ans = "Yes";
                break;
            }
        }
        
        System.out.println(ans);
        
    }
}
