Problem:
Score: 300 points

Problem Statement

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

1 0 1
2 1 2
1 0 1

Sample Output 1

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.

Sample Input 2

2 2 2
2 1 2
2 2 2

Sample Output 2

No

Takahashi is incorrect in this case.

Sample Input 3

0 8 8
0 8 8
0 8 8

Sample Output 3

Yes

Sample Input 4

1 8 6
2 9 7
0 7 7

Sample Output 4

No

Solution in JavaScript (Node.js 12.16.1) (judge verdict: Accepted)

const input = require("fs").readFileSync("/dev/stdin", "utf8")

;(input => {
  
  const lines = input.split('\n')
  
  const map = []
  for (let i = 0; i < 3; i++) {
    map[i] = lines[i].split(' ').map(Number)
  }
  
  let diff1 = 0
  let diff2 = 0

  diff1 = map[0][0] - map[0][1]
  diff2 = map[0][1] - map[0][2]

  
  for (var i = 1; i < 3; i++) {
      if (diff1 !== map[i][0] - map[i][1]) break
      if (diff2 !== map[i][1] - map[i][2]) break
  }
  
  console.log(i === 3 ? 'Yes' : 'No')
 
})(input)