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 C++ (GCC 5.4.1) (judge verdict: Accepted)

#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<string>
#include<cstdlib>
#include<algorithm>
using namespace std;
int st[4];
string st1;
int shu;
int main()
{
cin>>st1;
for(int i=0; i<4; i++)st[i]=int(st1[i])-48;
shu=st[0];
for(int i=1; i<=2; i++)
{
    if(i==1)shu+=st[1];
    else shu-=st[1];
    for(int j=1; j<=2; j++)
    {
        if(j==1)shu+=st[2]; 
        else shu-=st[2];
        for(int k=1; k<=2; k++)
        {
            if(k==1)shu+=st[3];
            else shu-=st[3];
            if(shu==7)
            {
                cout<<st[0]; 
                if(i==1)cout<<'+';
                else cout<<'-'; 
                cout<<st[1]; 
                if(j==1)cout<<'+'; 
                else cout<<'-'; 
                cout<<st[2]; 
                if(k==1)cout<<'+'; 
                else cout<<'-'; 
                cout<<st[3]; 
                cout<<"=7"; 
                cout<<endl; 
                return 0; 
            }
            if(k==1)shu-=st[3];
            else shu+=st[3]; 
        }
        if(j==1)shu-=st[2];
        else shu+=st[2]; 
    }
    if(i==1)shu-=st[1];
    else shu+=st[1];//恢复原样 
}
return 0;
}