#include <iostream>
#include <vector>
#include <algorithm>
#include <cstdio>
#define FOR(i, k, n) for(int i = k ; i < n ; i++)
void fast() {std::ios_base::sync_with_stdio(false) ; std::cin.tie(0) ; std::cout.tie(0);}
typedef long long int lld  ;
lld gcd(lld a, lld b){ if(!a) return b ; return gcd(b%a, a) ;}
template <class T> void print(T a) {std::cout << a << "\n" ;}
const int MAX = 111111 ;

// CODE FROM HERE
int original_array[MAX] ;
std::vector <int> ans ;
int main(){
//    fast() ;
    freopen("input.txt", "r", stdin) ;
//    freopen("output.txt", "w", stdout) ;

    int t, n, k ;
    std::cin >> t ;

    lld count_ = 0 ;
    while(t--){
        std::cin >> n >> k ;
        FOR(i, 1, n + 1) std::cin >> original_array[i] ;

        ans.assign(n + 5, 0) ;

        int vis = n, inverse_divisor ;
        for(int cur_size = n ; cur_size >= 1 ; cur_size--){
            vis = cur_size ;
            int element = original_array[cur_size] ;
            inverse_divisor = 1e9 ;

            for(int divisor = 1 ; divisor <= cur_size ; divisor++){
                if(cur_size < divisor) break ;
                if(divisor >= inverse_divisor) break ;

                count_++ ;
                int diff ;
                if(divisor == 1){
                    diff = 0 ;
                }
                else
                    diff = element/(divisor - 1) - element/divisor ;

                ans[cur_size - divisor + 1] -= diff ;

                inverse_divisor = element/divisor + 1 ;
                if(divisor >= inverse_divisor) break ;

                if(cur_size - inverse_divisor + 1 >= 0)
                    ans[cur_size - (inverse_divisor) + 1] -= 1 ;
            }
        }

        ans[n + 1] = 0 ;
        for(int i = n ; i >= 1 ; i--){
            ans[i] = ans[i] + original_array[i] + ans[i + 1] ;
        }

        int pos = n + 1 ;
        FOR(i, 1, n + 1){
            if(ans[i] <= k){
                pos = i ;
                break ;
            }
        }
        print(pos) ;
    }
//    std::cout << "coutn: " << 5*count_ << "\n" ;
}
//1 5 3
//2 2 1
//5 1 1
// FOUND PATTERN THROUGH THIS std::cout << j << " " << b/j << " " << b/j - b/(j + 1) << "\n" ; :))