#include<bits/stdc++.h>
#define int long long
using namespace std;
const int inf=1e16;
multiset<int>s1,s2;
int zuo,you,zhong,n,k,ans;
bool jiou=0;
int a[200000];
inline int read() {
    int sum = 0, ff = 1; char c = getchar();
    while(c<'0' || c>'9') { if(c=='-') ff = -1; c = getchar(); }
    while(c>='0'&&c<='9') { sum = sum * 10 + c - '0'; c = getchar(); }
    return sum * ff;
}
void init(){
    s1.clear();s2.clear();//s1<s2
    s1.insert(-inf);s2.insert(inf);
    zuo=you=zhong=0;
    jiou=0;
}

inline void add(int x) {
    //偶
    if(!jiou) {
        int A = *(--s1.end());
        int B = *s2.begin();
        if(A<=x && x<=B) { zhong = x; }
        else if(A>x) {
            s1.erase(s1.find(A));
            s1.insert(x);
            zuo += x-A;
            zhong = A;
        }
        else if(B<x) {
            s2.erase(s2.find(B));
            s2.insert(x);
            you += x-B;
            zhong = B;
        }
    }
    //奇
    else {
        if(x>=zhong) {
            s1.insert(zhong); zuo += zhong;
            s2.insert(x); you += x;
        }
        else {
            s2.insert(zhong); you += zhong;
            s1.insert(x); zuo += x;
        }
        zhong = 0;
    }
    jiou ^= 1;
}

inline void del(int x) {
    int A = *(--s1.end());
    int B = *s2.begin();
    if(!jiou) {
        if(A>=x) {
            s1.erase(s1.find(x)); zuo -= x;
            s2.erase(s2.find(B)); you -= B;
            zhong = B;
        }
        else {
            s2.erase(s2.find(x)); you -= x;
            s1.erase(s1.find(A)); zuo -= A;
            zhong = A;
        }
    }
    else {
        if(zhong==x) {}
        else if(x>zhong) {
            s2.erase(s2.find(x));
            s2.insert(zhong);
            you += zhong-x;
        }
        else {
            s1.erase(s1.find(x));
            s1.insert(zhong);
            zuo += zhong-x;
        }
        zhong = 0;
    }
    jiou ^= 1;
}

signed main(){
    int t;t=read();
    while(t--){
        init();
        n=read(),k=read();
        for(int i=1;i<=n;i++)a[i]=read()-i;
        a[n+1]=inf;
        int now=1;
        ans=1;
        add(a[1]);jiou=1;
        //滑动窗口
        for(int i=1;i<=n;i++){
            while(you-zuo<=k){
                ans=max(ans,now-i+1);
                add(a[++now]);
                
            }del(a[i]);
        }
        cout<<ans<<endl;

    }





    return 0;
}