#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define vll vector<ll>
#define vvll vector<vll>
#define mll map<ll,ll>
#define f(i,m,n)   for(i=m;i<n;i++)
#define rf(i,n,m)  for(i=n;i>=m;i--)
#define ee endl
#define Ee endl
#define pb push_back
#define ff first
#define ss second
#define take(v,n) for(i=0;i<n;i++) cin>>v[i];
#define print(v) for(i=0;i<(int)v.size();i++) cout<<v[i]<<" ";
#define print1(a)       cout<<a<<endl;
#define print2(a,b)     cout<<a<<" "<<b<<endl;
#define print3(a,b,c)   cout<<a<<" "<<b<<" "<<c<<endl;
#define print4(a,b,c,d) cout<<a<<" "<<b<<" "<<c<<" "<<d<<endl;
#define fast ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define sot(v) sort(v.begin(),v.end());
#define all(v) (v.begin(),v.end());
#define PI 3.14159265   ;
const ll mod =1e9+7;
void no()
{
    cout<<"NO"<<ee;
}
void yes()
{
    cout<<"YES"<<ee;
}
bool isPrime(int n)
{
    if (n <= 1)  return false;
    if (n <= 3)  return true;
    if (n % 2 == 0 || n % 3 == 0) return false;
    for (int i = 5; i*i <= n; i = i + 6)
        if (n%i == 0 || n % (i + 2) == 0)
            return false;
    return true;
}
ll powe(ll x, ll y) {
    ll res = 1;
    while (y > 0) {
        if (y & 1) res =( res * x)%mod;
        y = y >> 1;
        x = (x * x)%mod;
    }
    return res;
}
void solve()
{
    ll i,j,n;
    ll k1,k2,k3,k4,k;
    cin>>n;
    vll v(n);
    take(v,n);
    ll ans=0;
    if(n==1)
    {
        cout<<v[0]<<ee;
        return;
    }
    for(i=1;i<n-1;i++)
    {
        if(v[i]>v[i-1] && v[i]>v[i+1])
        {
            ans+=(v[i]-max(v[i-1],v[i+1]));
            v[i]=max(v[i-1],v[i+1]);
        }
    }
    if(v[0]>v[1])
    {
        ans+=(v[0]-v[1]);
        v[0]=v[1];
    }

    if(v[n-1]>v[n-2])
    {
        ans+=(v[n-1]-v[n-2]);
        v[n-1]=v[n-2];
    }
   // print(v);
    ans+=v[0]+v[n-1];
    //cout<<ans<<ee;
    for(i=1;i<n;i++)
    {
        ans+=(abs(v[i]-v[i-1]));
    }
    cout<<ans<<ee;
}

int main() {
    #ifndef ONLINE_JUDGE 
        freopen("input.txt", "r", stdin); 
        freopen("output.txt", "w", stdout); 
    #endif
    fast;
    ll i, j, l, k, t, n;
    cin>>t;
    //t=1;
    for (i = 1; i <= t; i++)
    {
        //cout<<"Case #"<<i<<": ";
        solve();
    }
}
