can you give me the answer of this test please:
4
10 10
20 20
10 20
20 10

my program writes 20 but I am not sure if this is the right answer
I STILL GOT WA!!

it's 13

wtf... ???? why can you explain

distance between first and second is 20 (|10-20 + 10-20|), between first and third is 10 (|10-10 + 10-20|), between first and fourt is 10 (|10-20 + 10-10|) so average for first is (20+10+10) / 3... do the same for second, third and fourth and result is (average for first + average for second + average for third + average for fourth) / n (in your case it's 4)

... and that is 20.

no, the correct answer for this test is 13.