# Type your text here
def convert_to_10(s, base):
    digits = "0123456789ABCDEF"
    s = s.upper()
    value = 0
    # Check user input is valid number in base
    for character in s:
        if character not in digits[:base]:
            print("Invalid digit '{}' for base {}".format(character, base))
            return None
        value = value * base + digits.index(character)
    return value

# Function to convert number (n) from base 10 to the given base (2–16).
def convert_from_10(n, base):
    if n == 0:
        return "0"
    digits = "0123456789ABCDEF"
    result = ""
    while n > 0:
        result = digits[n % base] + result
        n //= base
    return result

#while loop to repeat
while True:
  # Prompts for user input
  print("Universal Base Converter")
  num_start = input("Enter the number: ")
  from_base = int(input("Convert from base (2-16): "))
  to_base = int(input("Convert to base (2-16): "))
  
  # Check user input is valid base
  if from_base < 2 or from_base > 16 or to_base < 2 or to_base > 16:
      print("Base must be between 2 and 16")
  else:
      # Convert all numbers to base 10
      base_10 = convert_to_10(num_start, from_base)
      if base_10 is not None:
          # Only show Base 10 value if it's not redundant
          if from_base != 10 and to_base != 10:
              print("Base 10 value:", base_10)
          
          # Compute and display the final result
          if to_base == 10:
              # No need to reconvert; just show base 10 value
              result = str(base_10)
          else:
              result = convert_from_10(base_10, to_base)
          
          print("Result:", result)