(Source: USSR Maths Olympiad)
200 hundred students are positioned in 10 rows and 20 columns at a school assembly.
From each of the 20 columns the shortest student is selected. The tallest of these 20 short students is tagged A. They return back to their places.
Next the tallest student from each row is selected, and from these tall students the shortest is tagged as B.
Which of the two students tagged is taller, assuming they are different people?