We fill in an n×n table with real numbers such that the sum of the numbers in each row and each coloumn equals 1. For which values of K is the following statement true: if the sum of the absolute values of the negative entries in the table is at most K, then it's always possible to choose n positive entries of the table such that each row and each coloumn contains exactly one of the chosen entries.Proposed by Dávid Bencsik, Budapest combinatoricsnumbers in a tablegraph theory