Ordered Array

There is an N×M two-dimensional array A of integers. The array is ordered if, for every two rows i, k and two columns j, l such that 1 ≤ i < k ≤ N and 1 ≤ j < l ≤ M, the inequality A[i][j] + A[k][l] ≤ A[i][l] + A[k][j] always holds.

Given a two-dimensional array, determine whether it is ordered.

The first line contains the number of arrays T.

Then the T arrays are given in order. For each array, the first line contains two integers N and M. Each of the next N lines contains M integers. The elements are given in the order A[1][1], A[1][2], …, A[1][M], A[2][1], …, A[N][M].

For each array, output one answer per line in the same order as the input.

Print YES if the array is ordered, and NO otherwise. The letter case must match exactly.

• 1 ≤ T ≤ 10
• 1 ≤ N, M ≤ 500
• -1,000,000 ≤ A[i][j] ≤ 1,000,000