find the first change and its position

Hello! I have a 100x10 matrix, I need to find the first change and its position (the number of this position is the right number). How do i do this?

A(100x1)=[20 20 20 20 20 14 10 10 10 10 10 .....]
A(100x2)=[140 150 140 140 120 110 100 100 100 100 100 .....]

I need to catch the moment when the values ​​decrease

The answer I should get
B1=6
B2=5

[Daniel M]

Wouldn't B2 = 3 since it goes from 150 to 140?

Answer 1

[darova]

Use diff and find

[Daniel M]

And you can use multiple outputs for find to determine which row the results come from.