Accumulative Effect

2^(15) = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.

What is the sum of the digits of the number 2^(1000)?

My solution in Ruby:

sum, number = 0, 2**1000
str = number.to_s
y = str.scan(/./)
y.each do |c|
	sum += c.to_i
end
puts sum