#include <iostream>
#include <cstring>
#include <cstdio>
#include <queue>
#define maxn 100010
#define LL long long

using namespace std;

int T,n,k,a[maxn],h[maxn];
priority_queue<int> q;

int main()
{
    scanf("%d",&T);
    while (T--)
    {
        while(!q.empty()) q.pop();
        memset(a,0,sizeof(a));
        memset(h,0,sizeof(h));
        scanf("%d%d",&n,&k);
        LL ans=0;
        for (int i=1;i<=n-1;i++) scanf("%d",&a[i]);
        for (int i=0;i<n;i++)
        {
            h[i]=a[i+1]+1;
            ans+=h[i];
            q.push(h[i]);
        }
        k--;
        while (k--)
        {
            int c=q.top();
            q.pop();
            ans-=c;
            c=1;
            q.push(c);
            ans++;
        }
        printf("%I64d\n",ans);
    }
    return 0;
}