input: Write a function to design a positive feedback loop for the given Python program. The function should modify the given program so that after each iteration of the loop, it checks if the loop counter has reached the maximum value. If it has, it prints a positive feedback message. The function should return the modified program as a string. If the input program is not a loop, the function should return the original program without any modifications.
  
  def positive_feedback_loop(program):
      if "for" not in program or "in range" not in program:
          return program
      modified_program = program.replace(":", ":\n    i += 1\n    if i == 10:\n        print(\"You've got it!\")")
      return modified_program
  
  assert positive_feedback_loop("for i in range(10):\n    print(\"hello\")") == "for i in range(10):\n    print(\"hello\")\n    i += 1\n    if i == 10:\n        print(\"You've got it!\")"
  assert positive_feedback_loop("for i in range(5):\n    print(\"world\")") == "for i in range(5):\n    print(\"world\")\n    i += 1\n    if i == 10:\n        print(\"You've got it!\")"
  assert positive_feedback_loop("print(\"no loop\")") == "print(\"no loop\")"
  assert positive_feedback_loop("while True:\n    print(\"infinite loop\")") == "while True:\n    print(\"infinite loop\")"
output: def positive_feedback_loop(program):
      if "for" not in program or "in range" not in program:
          return program
      modified_program = program.replace(":", ":\n    i += 1\n    if i == 10:\n        print(\"You've got it!\")")
      return modified_program