#include <iostream>
#include <cstring>
#include <cmath>
#include <vector>
#include <string>
#include <map>
#include <algorithm>
#include <cstdio>
#include <stack>
#include <queue>
#include <cstdlib>
#include <set>
#define sqr(x) (x) * (x)
using namespace std;

const int MAX_SIZE = int(1e5+5);
const long long MOD = int(1e9+7);
const double EPS = 1e-9;

int T, n;
long long k;


int findLongestRainbowSubarray(vector<long long> &a, vector<long long> &psum, vector<long double> &psumSqr, long long k) {
    int ans = 1;
    int l = 1, r = n;
    while (l <= r) {
        int len = (l+r) >> 1;
        int index = len;
        long double criteria = (long double)1e35;
        for (int i=len; i<=n; i++) {
            long long sum = psum[i] - psum[i-len];
            long long avg = sum / len;
            long double f = (psumSqr[i] - psumSqr[i-len]) / len - sqr(avg);
            if (f + EPS <= criteria) {
                criteria = f;
                index = i;
            }
        }
        long long sum = psum[index] - psum[index-len];
        vector<long long> f(2, 0);
        long long avg = sum / len;
        for (int j=0; j<len; j++) {
            f[0] += abs(a[index-len+j+1] - (avg + j - len / 2));
            f[1] += abs(a[index-len+j+1] - (avg + j - len / 2 + 1));
        }
        long long need = min(f[0], f[1]);
        if (need <= k) {
            ans = max(ans, len);
            l = len+1;
        }
        else r = len-1;
    }
    return ans;
}


void solve() {
    cin >> T;
    while (T--) {
        cin >> n >> k;
        vector<long long> a(n+1);
        vector<long long> psum(n+1, 0);
        vector<long double> psumSqr(n+1, 0);
        for (int i=1; i<=n; i++) {
            cin >> a[i];
            psum[i] = psum[i-1] + a[i];
            psumSqr[i] = psumSqr[i-1] + sqr(a[i]);
        }
        cout << findLongestRainbowSubarray(a, psum, psumSqr, k) << endl;
    }
}


int main() {
    // freopen("inp.txt", "r", stdin);

    //Boost C++ IO speed
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    solve();    
    return 0;
}