#include<cstdio>#include<cstring>#include<cmath>#include<algorithm>using namespace std;struct node{ long long value; long long weight; int num;}box[20];int n;long long m;long long ans;long long sum[20]; bool cmp(const node &a,const node &b) {return a.value*1.0/a.weight>b.value*1.0/b.weight;}inline bool cut(int pos,long long value,long long left){ if(pos==n+1) return true;if(value+sum[pos]<=ans) return true; double best=(box[pos].value*1.0/box[pos].weight); if(value+(long long)ceil(best*left)<=ans) return true; return false;}void dfs(int pos,long long value,long long left){ ans=max(ans,value); if(cut(pos,value,left)) return; for(int i=box[pos].num;i>=0;i--){ if(left-box[pos].weight*i<0) continue; dfs(pos+1,value+box[pos].value*i,left-box[pos].weight*i); }}int main(){ int cas; long long sumv; long long sumw; scanf("%d",&cas); while(cas--) { ans=0; sumv=sumw=0; scanf("%d%lld",&n,&m); for(int i=1;i<=n;i++) { scanf("%lld",&box[i].weight); sumw+=box[i].weight*i; } for(int i=1;i<=n;i++) { scanf("%lld",&box[i].value); box[i].num=i; sumv+=box[i].value*i; } if(sumw<=m) { printf("%lldn",sumv); continue; } sort(box+1,box+1+n,cmp); sum[n+1]=0; for(int i=n;i>=1;i--) { sum[i]=sum[i+1]+box[i].value*box[i].num; } dfs(1,0,m); printf("%lldn",ans); } return 0;}
