Problem:
Score : 300 points

Problem 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.

Constraints

0≤A,B,C,D≤9

All input values are integers.

It is guaranteed that there is a solution.

Input

Input is given from Standard Input in the following format:

ABCD

Output

Print the formula you made, including the part =7.

Use the signs + and -.

Do not print a space between a digit and a sign.

Sample Input 1

1222

Sample Output 1

1+2+2+2=7

This is the only valid solution.

Sample Input 2

0290

Sample Output 2

0-2+9+0=7

0 - 2 + 9 - 0 = 7 is also a valid solution.

Sample Input 3

3242

Sample Output 3

3+2+4-2=7

Solution in JavaScript (node.js v5.12) (judge verdict: Accepted)

function Main(s) {
  var s = s.split("\n")[0].split("");
  var op = ["+","-"];
  for (var bit = 0; bit < (1<<3); bit++) {
    var ops = [];
    for (var i = 0; i < 3; i++) {
      if (bit & (1<<i)) {
        ops.push(op[0]);
      } else {
        ops.push(op[1]);
      }
    }
    var ans = s[0] + ops[0] + s[1] + ops[1] + s[2] + ops[2] + s[3];
    if (eval(ans) === 7) {
      console.log(ans + "=7");
      return;
    }
  }
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));