Final step to store all the column number of 1 st and 3 rd cell upto MidRow
for j in range ( min ( v [ i ] [ 0 ] , MidRow ) , max ( v [ i ] [ 0 ] , MidRow ) + 1 ) : NEW_LINE INDENT s . add ( ( j , v [ i ] [ 1 ] ) ) ; NEW_LINE DEDENT return len ( s ) NEW_LINE