#include <bits/stdc++.h>

using i64 = long long;

void sol() {
    int n;
    std::cin >> n;

    i64 k;
    std::cin >> k;

    std::vector<int> a(n);
    for (int i = 0 ; i < n; i++) {
        std::cin >> a[i];
        a[i] -= i;
    }

    int l = 0, r = 0;
    int ans = 0;
    
    auto cal = [](std::vector<int>& a) {
        int n = a.size();
        sort(a.begin(), a.end());
        int mid = a[n / 2];
        int opt = 0;

        for (int i = 0; i < n; ++i) {
            opt += abs(a[i] - mid);
        }
    
        return opt;
    };

    while (r < n) {
        std::vector<int> b;
        for (int i = l; i <= r; ++i) {
            b.push_back(a[i]);
        }
        int opt = cal(b);
        
        if (opt <= k) {
            ans = std::max(ans, r - l + 1);
            r++;
        } else {
            l++;
        }
    }

    std::cout << ans << "\n";
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int _;
    std::cin >>_;

    while (_--) {
        sol();
    }

    return 0;
}