give m x n binary matrix mat return number special position matA position j call special matij 1 element row column j 0 row column 0indexe example 1input mat 100001100output 1explanation 1 2 special position mat12 1 element row 1 column 2 0example 2input mat 100010001output 3explanation 0 0 1 1 2 2 special position Constraintsm matlengthn matilength1 m n 100matij 0 1