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();
			}
		}

		int a[] = new int[3];
		int b[] = new int[3];

		boolean ans = false;

		for (int n = 0; n <= c[0][0]; n++) {
			a[0] = n;
			b[0] = c[0][0] - a[0];
			b[1] = c[0][1] - a[0];
			b[2] = c[0][2] - a[0];

			a[1] = c[1][0] - b[0];
			a[2] = c[2][0] - b[0];

			loop: for (int i = 0; i < 3; i++) {
				for (int j = 0; j < 3; j++) {
					if(c[i][j] == a[i] + b[j]) {
						ans = true;
					} else {
						ans = false;
						break loop;
					}
				}
			}
		}
		if (ans) {
			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) {

		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];

		boolean ans = false;

		for (int n = 0; n <= c[0][0]; n++) {
			a[0] = n;
			b[0] = c[0][0] - a[0];
			b[1] = c[0][1] - a[0];
			b[2] = c[0][2] - a[0];

			a[1] = c[1][0] - b[0];
			a[2] = c[2][0] - b[0];

			loop: for (int i = 0; i < 3; i++) {
				for (int j = 0; j < 3; j++) {
					if(c[i][j] == a[i] + b[j]) {
						ans = true;
					} else {
						ans = false;
						break loop;
					}
				}
			}
		}
		if (ans) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}
	}
} 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];

		boolean ans = false;

		for (int n = 0; n <= c[0][0]; n++) {
			a[0] = n;
			b[0] = c[0][0] - a[0];
			b[1] = c[0][1] - a[0];
			b[2] = c[0][2] - a[0];

			a[1] = c[1][0] - b[0];
			a[2] = c[2][0] - b[0];

			loop: for (int i = 0; i < 3; i++) {
				for (int j = 0; j < 3; j++) {
					if(c[i][j] == a[i] + b[j]) {
						ans = true;
					} else {
						ans = false;
						break loop;
					}
				}
			}
		}
		if (ans) {
			System.out.println("Yes");
		} else {
			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];

		boolean ans = false;

		for (int n = 0; n <= c[0][0]; n++) {
			a[0] = n;
			b[0] = c[0][0] - a[0];
			b[1] = c[0][1] - a[0];
			b[2] = c[0][2] - a[0];

			a[1] = c[1][0] - b[0];
			a[2] = c[2][0] - b[0];

			loop: for (int i = 0; i < 3; i++) {
				for (int j = 0; j < 3; j++) {
					if(c[i][j] == a[i] + b[j]) {
						ans = true;
					} else {
						ans = false;
						break loop;
					}
				}
			}
		}
		if (ans) {
			System.out.println("Yes");
		} else {
			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 boolean ans = false; ans false for (int n = 0; n <= c[0][0]; n++) {
			a[0] = n;
			b[0] = c[0][0] - a[0];
			b[1] = c[0][1] - a[0];
			b[2] = c[0][2] - a[0];

			a[1] = c[1][0] - b[0];
			a[2] = c[2][0] - b[0];

			loop: for (int i = 0; i < 3; i++) {
				for (int j = 0; j < 3; j++) {
					if(c[i][j] == a[i] + b[j]) {
						ans = true;
					} else {
						ans = false;
						break loop;
					}
				}
			}
		} int n = 0; int n = 0; n 0 n <= c[0][0] n c[0][0] c[0] c 0 0 n++ n++ n {
			a[0] = n;
			b[0] = c[0][0] - a[0];
			b[1] = c[0][1] - a[0];
			b[2] = c[0][2] - a[0];

			a[1] = c[1][0] - b[0];
			a[2] = c[2][0] - b[0];

			loop: for (int i = 0; i < 3; i++) {
				for (int j = 0; j < 3; j++) {
					if(c[i][j] == a[i] + b[j]) {
						ans = true;
					} else {
						ans = false;
						break loop;
					}
				}
			}
		} {
			a[0] = n;
			b[0] = c[0][0] - a[0];
			b[1] = c[0][1] - a[0];
			b[2] = c[0][2] - a[0];

			a[1] = c[1][0] - b[0];
			a[2] = c[2][0] - b[0];

			loop: for (int i = 0; i < 3; i++) {
				for (int j = 0; j < 3; j++) {
					if(c[i][j] == a[i] + b[j]) {
						ans = true;
					} else {
						ans = false;
						break loop;
					}
				}
			}
		} a[0] = n a[0] a 0 n b[0] = c[0][0] - a[0] b[0] b 0 c[0][0] - a[0] c[0][0] c[0] c 0 0 a[0] a 0 b[1] = c[0][1] - a[0] b[1] b 1 c[0][1] - a[0] c[0][1] c[0] c 0 1 a[0] a 0 b[2] = c[0][2] - a[0] b[2] b 2 c[0][2] - a[0] c[0][2] c[0] c 0 2 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 (ans) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		} ans {
			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) {

		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];

		boolean ans = false;

		for (int n = 0; n <= c[0][0]; n++) {
			a[0] = n;
			b[0] = c[0][0] - a[0];
			b[1] = c[0][1] - a[0];
			b[2] = c[0][2] - a[0];

			a[1] = c[1][0] - b[0];
			a[2] = c[2][0] - b[0];

			loop: for (int i = 0; i < 3; i++) {
				for (int j = 0; j < 3; j++) {
					if(c[i][j] == a[i] + b[j]) {
						ans = true;
					} else {
						ans = false;
						break loop;
					}
				}
			}
		}
		if (ans) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}
	}
} 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];

		boolean ans = false;

		for (int n = 0; n <= c[0][0]; n++) {
			a[0] = n;
			b[0] = c[0][0] - a[0];
			b[1] = c[0][1] - a[0];
			b[2] = c[0][2] - a[0];

			a[1] = c[1][0] - b[0];
			a[2] = c[2][0] - b[0];

			loop: for (int i = 0; i < 3; i++) {
				for (int j = 0; j < 3; j++) {
					if(c[i][j] == a[i] + b[j]) {
						ans = true;
					} else {
						ans = false;
						break loop;
					}
				}
			}
		}
		if (ans) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}
	}
} 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();
			}
		}

		int a[] = new int[3];
		int b[] = new int[3];

		boolean ans = false;

		for (int n = 0; n <= c[0][0]; n++) {
			a[0] = n;
			b[0] = c[0][0] - a[0];
			b[1] = c[0][1] - a[0];
			b[2] = c[0][2] - a[0];

			a[1] = c[1][0] - b[0];
			a[2] = c[2][0] - b[0];

			loop: for (int i = 0; i < 3; i++) {
				for (int j = 0; j < 3; j++) {
					if(c[i][j] == a[i] + b[j]) {
						ans = true;
					} else {
						ans = false;
						break loop;
					}
				}
			}
		}
		if (ans) {
			System.out.println("Yes");
		} else {
			System.out.println("No");
		}
	}
}
