
import java.util.Scanner;

public class Main {
    public static void main(final String[] args) {
        final Scanner scanner = new Scanner(System.in);
        final int[][] table = new int[3][3];
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                table[i][j] = scanner.nextInt();
            }
        }

        int a1 = 0;
        int a2 = 0;
        int a3 = 0;
        int b1 = 0;
        int b2 = 0;
        int b3 = 0;

        for (a1 = 0; a1 <= table[0][0]; a1++) {
            b1 = table[0][0] - a1;
            a2 = table[1][0] - b1;
            if (a2 < 0) continue;
            a3 = table[2][0] - b1;
            if (a3 < 0) continue;
            b2 = table[0][1] - a1;
            if (b2 < 0) continue;
            b3 = table[0][2] - a1;
            if (b3 < 0) continue;
            if (a2 + b2 != table[1][1]) continue;
            if (a2 + b3 != table[1][2]) continue;
            if (a3 + b2 != table[2][1]) continue;
            if (a3 + b3 != table[2][2]) continue;
            System.out.println("Yes");
            return;
        }

        System.out.println("No");
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(final String[] args) {
        final Scanner scanner = new Scanner(System.in);
        final int[][] table = new int[3][3];
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                table[i][j] = scanner.nextInt();
            }
        }

        int a1 = 0;
        int a2 = 0;
        int a3 = 0;
        int b1 = 0;
        int b2 = 0;
        int b3 = 0;

        for (a1 = 0; a1 <= table[0][0]; a1++) {
            b1 = table[0][0] - a1;
            a2 = table[1][0] - b1;
            if (a2 < 0) continue;
            a3 = table[2][0] - b1;
            if (a3 < 0) continue;
            b2 = table[0][1] - a1;
            if (b2 < 0) continue;
            b3 = table[0][2] - a1;
            if (b3 < 0) continue;
            if (a2 + b2 != table[1][1]) continue;
            if (a2 + b3 != table[1][2]) continue;
            if (a3 + b2 != table[2][1]) continue;
            if (a3 + b3 != table[2][2]) continue;
            System.out.println("Yes");
            return;
        }

        System.out.println("No");
    }
} Main public static void main(final String[] args) {
        final Scanner scanner = new Scanner(System.in);
        final int[][] table = new int[3][3];
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                table[i][j] = scanner.nextInt();
            }
        }

        int a1 = 0;
        int a2 = 0;
        int a3 = 0;
        int b1 = 0;
        int b2 = 0;
        int b3 = 0;

        for (a1 = 0; a1 <= table[0][0]; a1++) {
            b1 = table[0][0] - a1;
            a2 = table[1][0] - b1;
            if (a2 < 0) continue;
            a3 = table[2][0] - b1;
            if (a3 < 0) continue;
            b2 = table[0][1] - a1;
            if (b2 < 0) continue;
            b3 = table[0][2] - a1;
            if (b3 < 0) continue;
            if (a2 + b2 != table[1][1]) continue;
            if (a2 + b3 != table[1][2]) continue;
            if (a3 + b2 != table[2][1]) continue;
            if (a3 + b3 != table[2][2]) continue;
            System.out.println("Yes");
            return;
        }

        System.out.println("No");
    } main {
        final Scanner scanner = new Scanner(System.in);
        final int[][] table = new int[3][3];
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                table[i][j] = scanner.nextInt();
            }
        }

        int a1 = 0;
        int a2 = 0;
        int a3 = 0;
        int b1 = 0;
        int b2 = 0;
        int b3 = 0;

        for (a1 = 0; a1 <= table[0][0]; a1++) {
            b1 = table[0][0] - a1;
            a2 = table[1][0] - b1;
            if (a2 < 0) continue;
            a3 = table[2][0] - b1;
            if (a3 < 0) continue;
            b2 = table[0][1] - a1;
            if (b2 < 0) continue;
            b3 = table[0][2] - a1;
            if (b3 < 0) continue;
            if (a2 + b2 != table[1][1]) continue;
            if (a2 + b3 != table[1][2]) continue;
            if (a3 + b2 != table[2][1]) continue;
            if (a3 + b3 != table[2][2]) continue;
            System.out.println("Yes");
            return;
        }

        System.out.println("No");
    } final Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) final int[][] table = new int[3][3]; table new int[3][3] 3 3 for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                table[i][j] = scanner.nextInt();
            }
        } int i = 0; int i = 0; i 0 i < 3 i 3 i++ i++ i {
            for (int j = 0; j < 3; j++) {
                table[i][j] = scanner.nextInt();
            }
        } {
            for (int j = 0; j < 3; j++) {
                table[i][j] = scanner.nextInt();
            }
        } for (int j = 0; j < 3; j++) {
                table[i][j] = scanner.nextInt();
            } int j = 0; int j = 0; j 0 j < 3 j 3 j++ j++ j {
                table[i][j] = scanner.nextInt();
            } {
                table[i][j] = scanner.nextInt();
            } table[i][j] = scanner.nextInt() table[i][j] table[i] table i j scanner.nextInt() scanner.nextInt scanner int a1 = 0; a1 0 int a2 = 0; a2 0 int a3 = 0; a3 0 int b1 = 0; b1 0 int b2 = 0; b2 0 int b3 = 0; b3 0 for (a1 = 0; a1 <= table[0][0]; a1++) {
            b1 = table[0][0] - a1;
            a2 = table[1][0] - b1;
            if (a2 < 0) continue;
            a3 = table[2][0] - b1;
            if (a3 < 0) continue;
            b2 = table[0][1] - a1;
            if (b2 < 0) continue;
            b3 = table[0][2] - a1;
            if (b3 < 0) continue;
            if (a2 + b2 != table[1][1]) continue;
            if (a2 + b3 != table[1][2]) continue;
            if (a3 + b2 != table[2][1]) continue;
            if (a3 + b3 != table[2][2]) continue;
            System.out.println("Yes");
            return;
        } a1 = 0; a1 = 0 a1 0 a1 <= table[0][0] a1 table[0][0] table[0] table 0 0 a1++ a1++ a1 {
            b1 = table[0][0] - a1;
            a2 = table[1][0] - b1;
            if (a2 < 0) continue;
            a3 = table[2][0] - b1;
            if (a3 < 0) continue;
            b2 = table[0][1] - a1;
            if (b2 < 0) continue;
            b3 = table[0][2] - a1;
            if (b3 < 0) continue;
            if (a2 + b2 != table[1][1]) continue;
            if (a2 + b3 != table[1][2]) continue;
            if (a3 + b2 != table[2][1]) continue;
            if (a3 + b3 != table[2][2]) continue;
            System.out.println("Yes");
            return;
        } {
            b1 = table[0][0] - a1;
            a2 = table[1][0] - b1;
            if (a2 < 0) continue;
            a3 = table[2][0] - b1;
            if (a3 < 0) continue;
            b2 = table[0][1] - a1;
            if (b2 < 0) continue;
            b3 = table[0][2] - a1;
            if (b3 < 0) continue;
            if (a2 + b2 != table[1][1]) continue;
            if (a2 + b3 != table[1][2]) continue;
            if (a3 + b2 != table[2][1]) continue;
            if (a3 + b3 != table[2][2]) continue;
            System.out.println("Yes");
            return;
        } b1 = table[0][0] - a1 b1 table[0][0] - a1 table[0][0] table[0] table 0 0 a1 a2 = table[1][0] - b1 a2 table[1][0] - b1 table[1][0] table[1] table 1 0 b1 if (a2 < 0) continue; a2 < 0 a2 0 continue; a3 = table[2][0] - b1 a3 table[2][0] - b1 table[2][0] table[2] table 2 0 b1 if (a3 < 0) continue; a3 < 0 a3 0 continue; b2 = table[0][1] - a1 b2 table[0][1] - a1 table[0][1] table[0] table 0 1 a1 if (b2 < 0) continue; b2 < 0 b2 0 continue; b3 = table[0][2] - a1 b3 table[0][2] - a1 table[0][2] table[0] table 0 2 a1 if (b3 < 0) continue; b3 < 0 b3 0 continue; if (a2 + b2 != table[1][1]) continue; a2 + b2 != table[1][1] a2 + b2 a2 b2 table[1][1] table[1] table 1 1 continue; if (a2 + b3 != table[1][2]) continue; a2 + b3 != table[1][2] a2 + b3 a2 b3 table[1][2] table[1] table 1 2 continue; if (a3 + b2 != table[2][1]) continue; a3 + b2 != table[2][1] a3 + b2 a3 b2 table[2][1] table[2] table 2 1 continue; if (a3 + b3 != table[2][2]) continue; a3 + b3 != table[2][2] a3 + b3 a3 b3 table[2][2] table[2] table 2 2 continue; 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" final String[] args args public class Main {
    public static void main(final String[] args) {
        final Scanner scanner = new Scanner(System.in);
        final int[][] table = new int[3][3];
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                table[i][j] = scanner.nextInt();
            }
        }

        int a1 = 0;
        int a2 = 0;
        int a3 = 0;
        int b1 = 0;
        int b2 = 0;
        int b3 = 0;

        for (a1 = 0; a1 <= table[0][0]; a1++) {
            b1 = table[0][0] - a1;
            a2 = table[1][0] - b1;
            if (a2 < 0) continue;
            a3 = table[2][0] - b1;
            if (a3 < 0) continue;
            b2 = table[0][1] - a1;
            if (b2 < 0) continue;
            b3 = table[0][2] - a1;
            if (b3 < 0) continue;
            if (a2 + b2 != table[1][1]) continue;
            if (a2 + b3 != table[1][2]) continue;
            if (a3 + b2 != table[2][1]) continue;
            if (a3 + b3 != table[2][2]) continue;
            System.out.println("Yes");
            return;
        }

        System.out.println("No");
    }
} public class Main {
    public static void main(final String[] args) {
        final Scanner scanner = new Scanner(System.in);
        final int[][] table = new int[3][3];
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                table[i][j] = scanner.nextInt();
            }
        }

        int a1 = 0;
        int a2 = 0;
        int a3 = 0;
        int b1 = 0;
        int b2 = 0;
        int b3 = 0;

        for (a1 = 0; a1 <= table[0][0]; a1++) {
            b1 = table[0][0] - a1;
            a2 = table[1][0] - b1;
            if (a2 < 0) continue;
            a3 = table[2][0] - b1;
            if (a3 < 0) continue;
            b2 = table[0][1] - a1;
            if (b2 < 0) continue;
            b3 = table[0][2] - a1;
            if (b3 < 0) continue;
            if (a2 + b2 != table[1][1]) continue;
            if (a2 + b3 != table[1][2]) continue;
            if (a3 + b2 != table[2][1]) continue;
            if (a3 + b3 != table[2][2]) continue;
            System.out.println("Yes");
            return;
        }

        System.out.println("No");
    }
} Main

import java.util.Scanner;

public class Main {
    public static void main(final String[] args) {
        final Scanner scanner = new Scanner(System.in);
        final int[][] table = new int[3][3];
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                table[i][j] = scanner.nextInt();
            }
        }

        int a1 = 0;
        int a2 = 0;
        int a3 = 0;
        int b1 = 0;
        int b2 = 0;
        int b3 = 0;

        for (a1 = 0; a1 <= table[0][0]; a1++) {
            b1 = table[0][0] - a1;
            a2 = table[1][0] - b1;
            if (a2 < 0) continue;
            a3 = table[2][0] - b1;
            if (a3 < 0) continue;
            b2 = table[0][1] - a1;
            if (b2 < 0) continue;
            b3 = table[0][2] - a1;
            if (b3 < 0) continue;
            if (a2 + b2 != table[1][1]) continue;
            if (a2 + b3 != table[1][2]) continue;
            if (a3 + b2 != table[2][1]) continue;
            if (a3 + b3 != table[2][2]) continue;
            System.out.println("Yes");
            return;
        }

        System.out.println("No");
    }
}
