#include<bits/stdc++.h>

#define int long long
#define mem(x,y) memset(x,y,sizeof(x))
#define frein freopen("in.in","r",stdin)
#define freout freopen("out.out","w",stdout)

using namespace std;

int read(){
   int s = 0,w = 1;
   char ch = getchar();
   while(ch < '0' || ch > '9'){if(ch == '-')w = -1;ch = getchar();}
   while(ch >= '0' && ch <= '9')s = s * 10 + ch - '0',ch = getchar();
   return s * w;
}

int t;
int n,m;
int a[1000010];
int sum;
int maxx;
int b[1000010];
int id[1000010];
int cnt;
int lst;
int l,r,mid;

signed main(){
    cin>>t;
    while(t --){
        maxx = -2147483647;
        lst = -2147483647;
        cnt = 0;
        sum = 0;
        n = read(),m = read();
        for(int i = 1;i <= n;i ++){
            a[i] = read();
            sum += a[i];
            maxx = max(maxx,sum);
            if(sum > lst){
                b[++ cnt] = sum;
                id[cnt] = i;
                lst = sum;
            }
        }
        while(m --){
            int ans = 0;
            int x;
            x = read();
            if(sum < 0){
                cout<<-1<<" ";
                continue;
            }
            if(maxx >= x){
                l = 1;
                r = cnt;
                int s = lower_bound(b + 1,b + cnt + 1,x) - b;
                ans += id[s];
                cout<<ans - 1<<" ";
                continue;
            }
            if(sum == 0){
                if(maxx < x){
                    cout<<-1<<" ";
                    continue;
                }
                else {
                    l = 1;
                    r = cnt;
                    int s = lower_bound(b + 1,b + cnt + 1,x) - b;
                    ans += id[s];
                    cout<<ans - 1<<" ";
                    continue;
                }
            }
            ans += (x - maxx + 1) / sum * n;
            x = x - ((x - maxx + 1) / sum * sum);
            if(x != 0){
                l = 1;
                r = cnt;
                int s = lower_bound(b + 1,b + cnt + 1,x) - b;
                ans += id[s];
            }
            cout<<ans - 1<<" ";
        }
        cout<<endl;
    }
}