A positive integer m is created so that its digit sum is 900 andwhen m is doubled, its digit sum does not change. The digits of minclude at least one of each of 3, 4, 5, and 6, and no otherdigits. Let m+ be the maximum such value of m, let m− be theminimum such value of m, and let P be the result of m+ × m−.Determine the number of digits of P .
