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A process with numbers

Source: 2019 Belarus Team Selection Test 6.2

September 2, 2019
combinatoricsProcessesalgebra

Problem Statement

The numbers 1,2,,49,501,2,\ldots,49,50 are written on the blackboard. Ann performs the following operation: she chooses three arbitrary numbers a,b,ca,b,c from the board, replaces them by their sum a+b+ca+b+c and writes (a+b)(b+c)(c+a)(a+b)(b+c)(c+a) to her notebook. Ann performs such operations until only two numbers remain on the board (in total 24 operations). Then she calculates the sum of all 2424 numbers written in the notebook. Let AA and BB be the maximum and the minimum possible sums that Ann san obtain. Find the value of AB\frac{A}{B}.
(I. Voronovich)