#include <bits/stdc++.h>
//#include "testlib.h"
using namespace std ;
#define LL long long int
#define ft first
#define sd second
#define PII pair<int,int>
#define MAXN 200005
#define MAXM 1001
#define mp make_pair
#define f_in(st) freopen(st,"r",stdin)
#define f_out(st) freopen(st,"w",stdout)
#define sc(x) scanf("%d",&x)
#define scll(x) scanf("%lld",&x)
#define pr(x) printf("%d\n",x)
#define prll(x) printf("%lld\n",x)
#define all(x) x.begin(),x.end()
#define pb push_back
#define MOD 1000003
#define ASST(x,l,r) assert(x >= l && x <= r)
 
 
int t , n , m ;
LL sum = 0 , pre ;
int main(){
    sc(t) ;
    while(t --){
        sc(n) ;
        pre = 0 ;
        sum = 0 ;
        while(n --){
            sc(m) ;
            sum += max(0LL,m-pre) ;
            pre = m ;
        }
        prll(sum) ;
    }
    return 0 ;
}