#include<bits/stdc++.h>
using namespace std;
int main(){
    int t,n,k;
    cin>>t;
    while(t--){
        cin>>n>>k;
        deque<int>q;
        vector<int>v(n);
        for(int i=0;i<n;i++){
            cin>>v[i];
            q.push_back(v[i]);
        }
        int init = q.size();
        int i= 1;
        
        while(k != 0 && q.size() != 0){
            if(i % 2 == 0){
                --q.back();
            }
            else{
                --q.front();
            }
            
            k--;
            i++;
            if(q.front() == 0){
                q.pop_front();
                continue;
            
            }
            if(q.back() == 0){
                q.pop_back();
                continue;
            }
        }
        
        cout<<init-q.size()<<endl;
    }
}