input: Write a python function to find the sum of the digits in the number N, then transform this sum into its binary equivalent.
  
  assert solve(1000) == "1"
  assert solve(150) == "110"
  assert solve(147) == "1100"
  assert solve(333) == "1001"
  assert solve(963) == "10010"
output: def solve(N):
      digit_sum = sum(int(digit) for digit in str(N))
      return bin(digit_sum)[2:]