output_description: Print the formula you made, including the part `=7`.
  
  Use the signs `+` and `-`.
  
  Do not print a space between a digit and a sign.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      ABCD
attempt: A, B, C, D = (int(T) for T in list(input()))
  ABCD = [
      A + B + C + D,
      A + B + C - D,
      A + B - C + D,
      A + B - C - D,
      A - B + C + D,
      A - B + C - D,
      A - B - C + D,
      A - B - C - D,
  ]
  Op = ["+++", "++-", "+-+", "+--", "-++", "-+-", "--+", "---"]
  Disp = list(Op[ABCD.index(7)])
  print("{}{}{}{}{}{}{}=7".format(A, Disp[0], B, Disp[1], C, Disp[2], D))
  
problem_description: Statement
  
  Sitting in a station waiting room, Joisino is gazing at her train ticket.
  
  The ticket is numbered with four digits A, B, C and D in this order, each
  between 0 and 9 (inclusive).
  
  In the formula A op1 B op2 C op3 D = 7, replace each of the symbols op1, op2
  and op3 with `+` or `-` so that the formula holds.
  
  The given input guarantees that there is a solution. If there are multiple
  solutions, any of them will be accepted.
samples: [{"input": "1222", "output": "1+2+2+2=7\n    \n\nThis is the only valid solution.\n\n* * *"}, {"input": "0290", "output": "0-2+9+0=7\n    \n\n0 - 2 + 9 - 0 = 7 is also a valid solution.\n\n* * *"}, {"input": "3242", "output": "3+2+4-2=7"}]