input: Write a function to generate an even number between 10 and 200 that is divisible by 5. If no such number is found, the function should return -1. 
  
  assert generate_even_number()==60
  assert generate_even_number()==40
  assert generate_even_number()==20
  assert generate_even_number()==100
  assert generate_even_number()==90
output: def generate_even_number():
      for num in range(10, 201, 2):
          if num % 5 == 0:
              return num
      return -1