#include<bits/stdc++.h> 
#define ll long long
using namespace std;
#define endl '\n'
const int N = 5e5 + 5;
ll a[N];
ll n, k;
void solve()
{
    cin >> n >> k;
    for (int i = 1;i <= n;i++) {
        cin >> a[i];
        a[i] += i;
    }
    ll l = 1, r = 1;
    ll ans = 1;
    multiset<ll>s1, s2;
    ll num = 0;
    ll cnt = 0;
    ll sum1 = 0, sum2 = 0;
    while (r <= n) {
        if ((r - l + 1) % 2) {
            if (s2.empty()) {
                s1.insert(a[r]);
                sum1 += a[r];
            }
            else if (*s2.begin() >= a[r]) {
                s1.insert(a[r]);
                sum1 += a[r];
            }
            else {
                int x = *s2.begin();
                s1.insert(x);
                s2.erase(s2.begin());
                s2.insert(a[r]);
                sum2 -= x;
                sum1 += x;
                sum2 += a[r];
            }
            cnt = sum1 - (s1.size()) * *prev(s1.end()) + (s2.size() * *prev(s1.end()) - sum2);
            cnt = abs(cnt);
        }
        else {
            if (s2.empty()) {
                s2.insert(a[r]);
                sum2 += a[r];
            }
            else if (*prev(s1.end()) > a[r]) {
                s2.insert(*prev(s1.end()));
                sum2 += *prev(s1.end());
                sum1 -= *prev(s1.end());
                s1.erase(prev(s1.end()));
                s1.insert(a[r]);
                sum1 += a[r];
            }
            else {
                s2.insert(a[r]);
                sum2 += a[r];
            }
            cnt = min((sum1 - (s1.size()) * *prev(s1.end()) + (s2.size() * *prev(s1.end()) - sum2)), (sum1 - (s1.size()) * *s2.begin() + (s2.size() * *s2.begin() - sum2)));
            cnt = abs(cnt);
        }
        while (cnt > k && l < r) {
            if ((s1.size() + s2.size()) & 1) {
                if (s1.find(a[l]) != s1.end()) {
                    s1.erase(s1.find(a[l]));
                    sum1 -= a[l];
                }
                else {
                    s2.erase(s2.find(a[l]));
                    sum2 -= a[l];
                    s2.insert(*prev(s1.end()));
                    sum2 += *prev(s1.end());
                    sum1 -= *prev(s1.end());
                    s1.erase(prev(s1.end()));
                }
                // sum -= a[l];
                cnt = min((sum1 - (s1.size()) * *prev(s1.end()) + (s2.size() * *prev(s1.end()) - sum2)), (sum1 - (s1.size()) * *s2.begin() + (s2.size() * *s2.begin() - sum2)));
                cnt = abs(cnt);
            }
            else {
                if (s1.find(a[l]) != s1.end()) {
                    s1.erase(s1.find(a[l]));
                    sum1 -= a[l];
                    sum1 += *s2.begin();
                    sum2 -= *s2.begin();
                    s1.insert(*s2.begin());
                    s2.erase(s2.begin());
                }
                else {
                    sum2 -= a[l];
                    s2.erase(s2.find(a[l]));
                }
                cnt = sum1 - (s1.size()) * *prev(s1.end()) + (s2.size() * *prev(s1.end()) - sum2);
                cnt = abs(cnt);
            }
            l++;
        }
        ans = max(ans, (r - l + 1));
        r++;
    }
    cout << ans << endl;
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int t;
    cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}