#include <bits/stdc++.h>
using namespace std;
#define M 500005
using ll = long long;
int f[M],A[M],n,mark[M];
int main(){
    int Cas;
    cin>>Cas;
    while(Cas--){
        scanf("%d",&n);
        for(int i=1;i<=n;i++)scanf("%d",&A[i]),mark[i]=0;
        ll ans = 0;
        int mx = 0;
        for(int i=1;i<=n;i++){
            if(mx<A[i])mx = A[i],mark[i]=1;
        }
        mx=0;
        for(int i=n;i>=1;i--){
            if(mx<A[i])mx = A[i],mark[i]=1;
        }
        for(int i=1,last=0;i<=n;i++){
            ans+=A[last];
            if(mark[i])last=i;
        }
        A[n+1]=0;
        for(int i=n,last=n+1;i>=1;i--){
            ans+=A[last];
            if(mark[i])last=i;
        }
        printf("%lld\n",ans);
    }
    return 0;
}