#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <time.h>
using namespace std;
int num[1111];
int n, p;

int main()
{
    //freopen("out", "w", stdout);
    //freopen("in", "r", stdin);
    int cases;
    scanf("%d", &cases);
    while(cases--) {
        scanf("%d%d", &n, &p);
        for(int i = 0; i < n; ++i) {
            scanf("%d", &num[i]);
        }
        long long ans = p;
        for(int i = 0; i < n; ++i) {
            swap(num[i], p);
            long long maxsum, sum;
            maxsum = sum = num[0];
            int flag = 0;
            for(int i = 0; i < n; ++i) {
                maxsum = max(maxsum, (long long)num[i]);
                if(num[i] >= 0) {
                    if(flag == 0) {
                        sum = 0;
                        flag = 1;
                    }
                }
                if(flag) {
                    if(sum < 0) sum = 0;
                    sum += num[i];
                }
                maxsum = max(maxsum, sum);
            }
            ans = max(ans, maxsum);
            swap(num[i], p);
        }
        printf("%I64d\n", ans);
    }
    return 0;
}