# include<bits/stdc++.h>

using namespace std;
# define l long long 
# define db double 
# define rep(i,a,b) for(l i=a;i<b;i++)
# define vi vector<l>
# define vvi vector<vi>
# define vsi vector<set<l> >
# define pb push_back
# define mp make_pair
# define ss second
# define ff first
# define pii pair<l,l>
# define trvi(v,it) for(vi::iterator it=v.begin();it!=v.end();++it)
# define read(a) freopen(a,"r",stdin)
# define write(a) freopen(a,"w",stdout)
# define io ios::sync_with_stdio(false)

template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ' ' << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { os << '{'; string sep; for (const T &x : v) os << sep << x, sep = ", "; return os << '}'; }
 

#ifdef KRISHNAN_DEBUG
void dbg_out() { cerr << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cerr << ' ' << H; dbg_out(T...); }
#define dbg(...) cerr << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...)
#endif

const bool MULTIPLE_TEST_CASES = true;

const l MOD=1e9+7;
const l N=1e5+5;
const l INF=1e12;

void solve() {
	l n;
	cin>>n;
	vi a(n+1,0), b(n+1,0);
	rep(i,1,n+1) {
		cin>>a[i]>>b[i];
	}
	vi tm(n+1,0);
	rep(i,1,n+1) {
		cin>>tm[i];
	}

	l current = 0;
	l time = 0;
	while(current<n) {
		l depart = max(b[current], time + (b[current] - a[current] + 1)/2);
		time = depart;
		time += a[current+1] - b[current] + tm[current+1];
		current++;
	}
	cout<<time<<"\n";
	return;
}


int main(){
	io;
	int t=1;
	if (MULTIPLE_TEST_CASES) cin>>t;
	rep(i,0,t) {
		solve();
	}

	return 0;
}
