you give m x n matrix mat row sort nondecrease order integer kYou allow choose exactly element row form arrayreturn kth small array sum possible array Example 1input mat 1311246 k 5output 7explanation choose element row k small sum are12 14 32 34 16 where 5th sum 7example 2input mat 1311246 k 9Output 17example 3input mat 11010145236 k 7Output 9explanation choose element row k small sum are112 113 142 143 116 152 153 where 7th sum 9 Constraintsm matlengthn matlengthi1 m n 401 matij 50001 k min200 nmmati nondecrease array