#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <queue>
#include <algorithm>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <memory.h>
#include <ctime>
#include <bitset>

using namespace std;

#define ABS(a) ((a>0)?a:-(a))
#define MIN(a,b) ((a<b)?(a):(b))
#define MAX(a,b) ((a<b)?(b):(a))
#define FOR(i,a,n) for (int i=(a);i<(n);++i)
#define FI(i,n) for (int i=0; i<(n); ++i)
#define pnt pair <int, int>
#define mp make_pair
#define PI 3.14159265358979
#define MEMS(a,b) memset(a,b,sizeof(a))
#define LL long long
#define U unsigned

int was[110][200100];
int n,t;
int a[110];
void dfs(int p, int sum)
{
    if (was[p][sum]==t)
        return;
    was[p][sum]=t;
    if (p==n)
        return;
    dfs(p+1,sum+a[p]);
    dfs(p+1,sum);
}

int main()
{
#ifdef Fcdkbear
    freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    double beg=clock();
#endif

    int num;
    scanf("%d",&num);
    for (t=1; t<=num; ++t)
    {
        int A;
        scanf("%d%d",&n,&A);
        int sum=0;
        FOR(i,0,n)
        {
            scanf("%d",&a[i]);
            sum+=a[i];
        }
        dfs(0,0);
        bool is=false;
        FOR(i,A/2,sum+1)
            if ((was[n][i]==t) && (i+i>=A))
            {
                is=true;
                printf("%d\n",i);
                break;
            }
        if (!is)
            printf("-1\n");
    }

#ifdef Fcdkbear
    double end=clock();
    fprintf(stderr,"*** Total time = %.3lf ***\n",(end-beg)/CLOCKS_PER_SEC);
#endif
}