lib C fun strtoll(s : UInt8*, p : UInt8**, b : Int32) : Int64 end class String def to_i64 C.strtoll(self, nil, 10) end end struct Int def prime_factor : Array(Tuple(self, Int32)) result = [] of Tuple(self, Int32) n = self typeof(self).new(2).upto(Math.sqrt(self).ceil) do |x| count = 0 while n % x == 0 n //= x count += 1 end result << {x, count} if count > 0 end result << {n, 1} if n != 1 result end def divisors : Array(self) result = [] of self each_divisor do |d| result << d end result end def divisor_pairs : Array({self, self}) divisors.map { |d| {d, self // d} } end def each_divisor(&) tmp = [] of self typeof(self).new(1).upto(self) do |x| break if x * x > self if self % x == 0 yield x tmp << x end end (0...tmp.size).reverse_each do |i| yield self // tmp[i] if tmp[i] * tmp[i] < self end end end n = read_line.to_i puts n.divisor_pairs.sum { |a, b| (0...32).reduce(1i64) do |acc, i| if a.bit(i) == 1 && b.bit(i) == 1 acc * 2 elsif a.bit(i) == 0 && b.bit(i) == 1 0i64 else acc end end } // 2