Find value of rows having first column value equal to zero
for i in range ( 0 , n ) : NEW_LINE INDENT if A [ i ] [ 0 ] == 0 : NEW_LINE INDENT ans = 0 NEW_LINE for j in range ( 1 , m ) : NEW_LINE INDENT ans = ans + A [ i ] [ j ] * 2 ** ( m - j - 1 ) NEW_LINE DEDENT update [ ans ] = i NEW_LINE DEDENT DEDENT