#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?

def sum_digits(n):
    sum = 0
    while n != 0:
        sum += n%10
        n = n//10
    return sum

print (sum_digits(pow(2, 1000)))
