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: abcd = str(input())
  abcd_list = list(abcd)
  a = int(abcd_list[0])
  b = int(abcd_list[1])
  c = int(abcd_list[2])
  d = int(abcd_list[3])
  ans2 = "+"
  ans3 = "+"
  ans4 = "+"
  for i in [a]:
      for j in [b, -b]:
          for k in [c, -c]:
              for l in [d, -d]:
                  ans = i + j + k + l
                  if ans == 7:
                      if j < 0:
                          ans2 = "-"
                      elif k < 0:
                          ans3 = "-"
                      elif l < 0:
                          ans4 = "-"
  print(str(a) + ans2 + str(b) + ans3 + str(c) + ans4 + str(d) + "=7")
  
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"}]