

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] = sc.nextInt();
			}
		}

		String ans = "No";

		if (c[0][0] - c[1][0] == c[0][1] - c[1][1] && c[0][0] - c[1][0] == c[0][2] - c[1][2])
			if (c[0][0] - c[2][0] == c[0][1] - c[2][1] && c[0][0] - c[2][0] == c[0][2] - c[2][2])
				if (c[1][0] - c[2][0] == c[1][1] - c[2][1] && c[1][0] - c[2][0] == c[1][2] - c[2][2])
					if (c[0][0] - c[0][1] == c[1][0] - c[1][1] && c[0][0] - c[2][1] == c[0][0] - c[2][1])
						if (c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2])
							if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes";

		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] = sc.nextInt();
			}
		}

		String ans = "No";

		if (c[0][0] - c[1][0] == c[0][1] - c[1][1] && c[0][0] - c[1][0] == c[0][2] - c[1][2])
			if (c[0][0] - c[2][0] == c[0][1] - c[2][1] && c[0][0] - c[2][0] == c[0][2] - c[2][2])
				if (c[1][0] - c[2][0] == c[1][1] - c[2][1] && c[1][0] - c[2][0] == c[1][2] - c[2][2])
					if (c[0][0] - c[0][1] == c[1][0] - c[1][1] && c[0][0] - c[2][1] == c[0][0] - c[2][1])
						if (c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2])
							if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes";

		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] = sc.nextInt();
			}
		}

		String ans = "No";

		if (c[0][0] - c[1][0] == c[0][1] - c[1][1] && c[0][0] - c[1][0] == c[0][2] - c[1][2])
			if (c[0][0] - c[2][0] == c[0][1] - c[2][1] && c[0][0] - c[2][0] == c[0][2] - c[2][2])
				if (c[1][0] - c[2][0] == c[1][1] - c[2][1] && c[1][0] - c[2][0] == c[1][2] - c[2][2])
					if (c[0][0] - c[0][1] == c[1][0] - c[1][1] && c[0][0] - c[2][1] == c[0][0] - c[2][1])
						if (c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2])
							if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes";

		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] = sc.nextInt();
			}
		}

		String ans = "No";

		if (c[0][0] - c[1][0] == c[0][1] - c[1][1] && c[0][0] - c[1][0] == c[0][2] - c[1][2])
			if (c[0][0] - c[2][0] == c[0][1] - c[2][1] && c[0][0] - c[2][0] == c[0][2] - c[2][2])
				if (c[1][0] - c[2][0] == c[1][1] - c[2][1] && c[1][0] - c[2][0] == c[1][2] - c[2][2])
					if (c[0][0] - c[0][1] == c[1][0] - c[1][1] && c[0][0] - c[2][1] == c[0][0] - c[2][1])
						if (c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2])
							if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes";

		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] = 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 String ans = "No"; ans "No" if (c[0][0] - c[1][0] == c[0][1] - c[1][1] && c[0][0] - c[1][0] == c[0][2] - c[1][2])
			if (c[0][0] - c[2][0] == c[0][1] - c[2][1] && c[0][0] - c[2][0] == c[0][2] - c[2][2])
				if (c[1][0] - c[2][0] == c[1][1] - c[2][1] && c[1][0] - c[2][0] == c[1][2] - c[2][2])
					if (c[0][0] - c[0][1] == c[1][0] - c[1][1] && c[0][0] - c[2][1] == c[0][0] - c[2][1])
						if (c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2])
							if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes"; c[0][0] - c[1][0] == c[0][1] - c[1][1] && c[0][0] - c[1][0] == c[0][2] - c[1][2] c[0][0] - c[1][0] == c[0][1] - c[1][1] c[0][0] - c[1][0] c[0][0] c[0] c 0 0 c[1][0] c[1] c 1 0 c[0][1] - c[1][1] c[0][1] c[0] c 0 1 c[1][1] c[1] c 1 1 c[0][0] - c[1][0] == c[0][2] - c[1][2] c[0][0] - c[1][0] c[0][0] c[0] c 0 0 c[1][0] c[1] c 1 0 c[0][2] - c[1][2] c[0][2] c[0] c 0 2 c[1][2] c[1] c 1 2 if (c[0][0] - c[2][0] == c[0][1] - c[2][1] && c[0][0] - c[2][0] == c[0][2] - c[2][2])
				if (c[1][0] - c[2][0] == c[1][1] - c[2][1] && c[1][0] - c[2][0] == c[1][2] - c[2][2])
					if (c[0][0] - c[0][1] == c[1][0] - c[1][1] && c[0][0] - c[2][1] == c[0][0] - c[2][1])
						if (c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2])
							if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes"; c[0][0] - c[2][0] == c[0][1] - c[2][1] && c[0][0] - c[2][0] == c[0][2] - c[2][2] c[0][0] - c[2][0] == c[0][1] - c[2][1] c[0][0] - c[2][0] c[0][0] c[0] c 0 0 c[2][0] c[2] c 2 0 c[0][1] - c[2][1] c[0][1] c[0] c 0 1 c[2][1] c[2] c 2 1 c[0][0] - c[2][0] == c[0][2] - c[2][2] c[0][0] - c[2][0] c[0][0] c[0] c 0 0 c[2][0] c[2] c 2 0 c[0][2] - c[2][2] c[0][2] c[0] c 0 2 c[2][2] c[2] c 2 2 if (c[1][0] - c[2][0] == c[1][1] - c[2][1] && c[1][0] - c[2][0] == c[1][2] - c[2][2])
					if (c[0][0] - c[0][1] == c[1][0] - c[1][1] && c[0][0] - c[2][1] == c[0][0] - c[2][1])
						if (c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2])
							if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes"; c[1][0] - c[2][0] == c[1][1] - c[2][1] && c[1][0] - c[2][0] == c[1][2] - c[2][2] c[1][0] - c[2][0] == c[1][1] - c[2][1] c[1][0] - c[2][0] c[1][0] c[1] c 1 0 c[2][0] c[2] c 2 0 c[1][1] - c[2][1] c[1][1] c[1] c 1 1 c[2][1] c[2] c 2 1 c[1][0] - c[2][0] == c[1][2] - c[2][2] c[1][0] - c[2][0] c[1][0] c[1] c 1 0 c[2][0] c[2] c 2 0 c[1][2] - c[2][2] c[1][2] c[1] c 1 2 c[2][2] c[2] c 2 2 if (c[0][0] - c[0][1] == c[1][0] - c[1][1] && c[0][0] - c[2][1] == c[0][0] - c[2][1])
						if (c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2])
							if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes"; c[0][0] - c[0][1] == c[1][0] - c[1][1] && c[0][0] - c[2][1] == c[0][0] - c[2][1] c[0][0] - c[0][1] == c[1][0] - c[1][1] c[0][0] - c[0][1] c[0][0] c[0] c 0 0 c[0][1] c[0] c 0 1 c[1][0] - c[1][1] c[1][0] c[1] c 1 0 c[1][1] c[1] c 1 1 c[0][0] - c[2][1] == c[0][0] - c[2][1] c[0][0] - c[2][1] c[0][0] c[0] c 0 0 c[2][1] c[2] c 2 1 c[0][0] - c[2][1] c[0][0] c[0] c 0 0 c[2][1] c[2] c 2 1 if (c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2])
							if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes"; c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2] c[0][0] - c[0][2] == c[1][0] - c[1][2] c[0][0] - c[0][2] c[0][0] c[0] c 0 0 c[0][2] c[0] c 0 2 c[1][0] - c[1][2] c[1][0] c[1] c 1 0 c[1][2] c[1] c 1 2 c[0][0] - c[0][2] == c[2][0] - c[2][2] c[0][0] - c[0][2] c[0][0] c[0] c 0 0 c[0][2] c[0] c 0 2 c[2][0] - c[2][2] c[2][0] c[2] c 2 0 c[2][2] c[2] c 2 2 if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes"; c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2] c[0][1] - c[0][2] == c[1][1] - c[1][2] c[0][1] - c[0][2] c[0][1] c[0] c 0 1 c[0][2] c[0] c 0 2 c[1][1] - c[1][2] c[1][1] c[1] c 1 1 c[1][2] c[1] c 1 2 c[0][1] - c[0][2] == c[2][1] - c[2][2] c[0][1] - c[0][2] c[0][1] c[0] c 0 1 c[0][2] c[0] c 0 2 c[2][1] - c[2][2] c[2][1] c[2] c 2 1 c[2][2] c[2] c 2 2 ans = "Yes" ans "Yes" 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] = sc.nextInt();
			}
		}

		String ans = "No";

		if (c[0][0] - c[1][0] == c[0][1] - c[1][1] && c[0][0] - c[1][0] == c[0][2] - c[1][2])
			if (c[0][0] - c[2][0] == c[0][1] - c[2][1] && c[0][0] - c[2][0] == c[0][2] - c[2][2])
				if (c[1][0] - c[2][0] == c[1][1] - c[2][1] && c[1][0] - c[2][0] == c[1][2] - c[2][2])
					if (c[0][0] - c[0][1] == c[1][0] - c[1][1] && c[0][0] - c[2][1] == c[0][0] - c[2][1])
						if (c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2])
							if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes";

		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] = sc.nextInt();
			}
		}

		String ans = "No";

		if (c[0][0] - c[1][0] == c[0][1] - c[1][1] && c[0][0] - c[1][0] == c[0][2] - c[1][2])
			if (c[0][0] - c[2][0] == c[0][1] - c[2][1] && c[0][0] - c[2][0] == c[0][2] - c[2][2])
				if (c[1][0] - c[2][0] == c[1][1] - c[2][1] && c[1][0] - c[2][0] == c[1][2] - c[2][2])
					if (c[0][0] - c[0][1] == c[1][0] - c[1][1] && c[0][0] - c[2][1] == c[0][0] - c[2][1])
						if (c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2])
							if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes";

		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] = sc.nextInt();
			}
		}

		String ans = "No";

		if (c[0][0] - c[1][0] == c[0][1] - c[1][1] && c[0][0] - c[1][0] == c[0][2] - c[1][2])
			if (c[0][0] - c[2][0] == c[0][1] - c[2][1] && c[0][0] - c[2][0] == c[0][2] - c[2][2])
				if (c[1][0] - c[2][0] == c[1][1] - c[2][1] && c[1][0] - c[2][0] == c[1][2] - c[2][2])
					if (c[0][0] - c[0][1] == c[1][0] - c[1][1] && c[0][0] - c[2][1] == c[0][0] - c[2][1])
						if (c[0][0] - c[0][2] == c[1][0] - c[1][2] && c[0][0] - c[0][2] == c[2][0] - c[2][2])
							if (c[0][1] - c[0][2] == c[1][1] - c[1][2] && c[0][1] - c[0][2] == c[2][1] - c[2][2])
								ans = "Yes";

		System.out.println(ans);

	}

}
