Mixing

#include<bits/stdc++.h>
using namespace std;
int a[1000010];
int main(){
    int q,n;
    scanf("%d",&q);
    while(q--){
        scanf("%d",&n);
        long long ans = 0;
        for(int i=1;i<=n;i++){
            scanf("%d",&a[i]);
            if(i>=2)
                ans+=max(a[i],a[i-1]);
        }
        printf("%lld\n",ans);
    }
    return 0;
}