#include <cstdio>#include <queue>#include <algorithm>#include <string.h>//#include <bits/stdc++.h>using namespace std;const int maxn=100000;int t;int a[maxn+10];int sum[maxn+10];int n,m;bool judge(int mid){    priority_queue<int,vector<int>,greater<int> > q;    int cnt=0;    int s=(n-1)%(mid-1);    if(s){        s++;        int temp=sum[(n-1)%(mid-1)+1];        q.push(temp);        cnt+=temp;    }    for(int i=s+1;i<=n;i++){        q.push(a[i]);    }    while(q.size()!=1){         int temp=0;         for(int i=1;i<=mid;i++){            if(!q.empty()){            temp+=q.top();            q.pop();            } else {               break;            }        }        q.push(temp);        cnt+=temp;    }    return cnt<=m;}int solve(){  int lb=2,ub=n;  while(ub-lb>1){       int mid=(ub+lb)>>1;       if(judge(mid)) ub=mid;       else lb=mid;  }  if(judge(lb)){      return lb;  } else return ub;}int main(){    scanf("%d",&t);    while(t--){       sum[0]=0;       scanf("%d%d",&n,&m);       if(n<=1){         printf("1\n");         continue;       }       for(int i=1;i<=n;i++){           scanf("%d",&a[i]);           sum[i]=sum[i-1]+a[i];       }       sort(a+1,a+1+n);       for(int i=1;i<=n;i++){           sum[i]=sum[i-1]+a[i];       }       //printf("%d\n",judge(3));       int ans=solve();       printf("%d\n",ans);    }    return 0;}