let id x = x
let n = Scanf.scanf "%s\n" id
let a = (int_of_char n.[0]) - 48
let b = (int_of_char n.[1]) - 48
let c = (int_of_char n.[2]) - 48
let d = (int_of_char n.[3]) - 48
let oplist = [1;0]

let i2op i = if i = 1 then (+) else (-)
let i2c i = if i = 1 then '+' else '-'
  
let rec loop3 op1 op2 l =
  match l with
  | [] -> []
  | op3 :: rest ->
     if (i2op op3) ((i2op op2) ((i2op op1) a b) c) d = 7 then (op1,op2,op3) :: loop3 op1 op2 rest
       else loop3 op1 op2 rest

let rec loop2 op1 l =
  match l with
  | [] -> []
  | op2 :: rest -> (loop3 op1 op2 oplist) @ loop2 op1 rest
     
let rec loop1 l =
  match l with
  | [] -> []
  | op1 :: rest -> (loop2 op1 oplist) @ loop1 rest
    
let (op1,op2,op3) = List.hd (loop1 oplist)
let (op1,op2,op3) = (i2c op1,i2c op2,i2c op3)
  
let () =
  Printf.printf "%d%c%d%c%d%c%d=7\n" a op1 b op2 c op3 d