#include <bits/stdc++.h>
using namespace std;
 
// Speed
#define fast_io ios::sync_with_stdio(0); cin.tie(0); cout.tie(0)
 
// Typedefs
#define int long long
#define pb push_back
#define ff first
#define ss second
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) ((int)(x).size())
#define endl '\n'
 
// Loops
#define rep(i,a,b) for(int i=a;i<b;++i)
#define each(x, a) for (auto &x : a)
 
void solve() {
    int n;
    cin>>n;
    vector<int> a(n);
    vector<int> b(n);
    rep(i,0,n) cin>>a[i];
    rep(i,0,n) cin>>b[i];
    int sum=0;
    rep(i,0,n){
    	sum=max(sum-a[i],b[i]-sum);
    }
    cout<<sum<<endl;
}
 
int32_t main() {
    fast_io;
    int t;
    cin >> t;
    while (t--) solve();
    return 0;
}
 

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3
3
4 -8 -1
-3 -7 0
5
-3 1 0 7 1
-5 3 -1 4 -5
5
-7 7 5 4 9
-9 -3 3 2 2