We have $a 3 \times 3 grid. A number c_{i, j}$ is written in the square (i, j), where (i, j) denotes the square at the i-th row from the top and the j-th column from the left.

According to Takahashi, there are six integers a_1, a_2, a_3, b_1, b_2, b_3 whose values are fixed, and the number written in the square (i, j) is equal to a_i + b_j.

Determine if he is correct.

-----Constraints-----
- c_{i, j} \ $(1 \leq i \leq 3, 1 \leq j \leq 3)$ is an integer between 0 and 100 (inclusive).

-----Input-----
Input is given from Standard Input in the following format:
c_{1,1} c_{1,2} c_{1,3}
c_{2,1} c_{2,2} c_{2,3}
c_{3,1} c_{3,2} c_{3,3}

-----Output-----
If Takahashi's statement is correct, print Yes; otherwise, print No.

-----Sample Input-----
1 0 1
2 1 2
1 0 1

-----Sample Output-----
Yes

Takahashi is correct, since there are possible sets of integers such as: a_1=0,a_2=1,a_3=0,b_1=1,b_2=0,b_3=1.

见题面

见题面