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<stdio.h>
#include<stdlib.h>
#include<math.h>
#include<string.h>
#include <time.h>
typedef long long ll;
typedef long double ld;
#define INF (1LL<<60)
/*swap 交換*/
void swap(ll *a, ll *b){ll c;c=*b;*b=*a;*a=c;}
/*2つのうち大きい数を返す*/
ll max2(ll a,ll b){return a>=b?a:b;}
/*2つのうち小さい数を返す*/
ll min2(ll a,ll b){return a>=b?b:a;}
/*絶対値*/
ll ABS(ll a){return a>=0?a:(-a);}
typedef struct{
    ll aa;
    ll bb;
}frequent;
// 小大
int compare(const void *a, const void *b){return *(ll *)a - *(ll *)b;}
ll trainticket(ll a, ll b, ll i){
    switch(i){
        case 0:
        return a+b;
        case 1:
        return a-b;
    }
    return 0;
}

int main(void){
    ll n,i,j,k,a,b,c,d,x,y,z;
    scanf("%lld",&n);
    a=n/1000;
    b=(n/100)%10;
    c=(n%100)/10;
    d=n%10;
    for(i=0;i<2;i++){
        x = trainticket(a,b,i);
        for(j=0;j<2;j++){
            y = trainticket(x,c,j);
            for(k=0;k<2;k++){
                z = trainticket(y,d,k);
                // printf("%lld\n",z);
                if(z==7) break;
            }
            if(k!=2) break;
        }
        if(j!=2) break;
    }
    printf("%lld",a);
    if(i==0){
        printf("+");
    }else{
        printf("-");
    }
    printf("%lld",b);
    if(j==0){
        printf("+");
    }else{
        printf("-");
    }
    printf("%lld",c);
    if(k==0){
        printf("+");
    }else{
        printf("-");
    }
    printf("%lld",d);
    printf("=7\n");
    return 0;
}