OK, let's do this. We've got 50686 and 15599, and we're subtracting the second number from the first.

Step 1: We'll start by subtracting the digit 9 and the borrow 0 from 6 in column 1 and get -3.
We add -3 to 10 and get 7 as the first digit of the result.

Step 2: We'll start by subtracting the digit 9 and the borrow 1 from 8 in column 2 and get -2.
We add -2 to 10 and get 8 as the next digit of the result.

Step 3: We'll start by subtracting the digit 5 and the borrow 1 from 6 in column 3 and get 0.
0 is the next digit of our result.

Step 4: We'll start by subtracting the digit 5 and the borrow 0 from 0 in column 4 and get -5.
We add -5 to 10 and get 5 as the next digit of the result.

Step 5: We'll start by subtracting the digit 1 and the borrow 1 from 5 in column 5 and get 3.
3 is the next digit of our result.

So, 50686 - 15599 = 35087.