#include <bits/stdc++.h>
//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,fma")
//#pragma GCC optimization ("unroll-loops")

#define int long long
#define pb emplace_back
#define all(s) s.begin(),s.end()
#define rall(s) s.rbegin(),s.rend()
#define pii pair<int,int>
#define fr first
#define sc second
#define bst ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define endl "\n"
#define no cout << "NO" << endl;
#define yes cout << "YES" << endl;

using namespace std;

const int N = 5e5 + 10, mod = 1e9 + 7, inf = 1e18 + 7, logn = 23;
const double pi = acos(-1);


void solve() {
	//soln
	int a[3], b[3]; // 0 1 2
	int ans = 0;
	for(int i = 0; i < 3; i++) {
  	cin >> a[i];
  }
  for(int i = 0; i < 3; i++) {
  	cin >> b[i];
  }
  int tmp;
  /*
     2 1 +
     2 2 =
     2 0 =
     1 2 -
     1 1 =
     1 0 =
     0 2 =
     0 1 =
     0 0 =

  */
 	if(min(a[2], b[1]) > 0) {
 		tmp = min(a[2], b[1]);
 		ans += 2 * tmp;
 		a[2] -= tmp;
 		b[1] -= tmp;
 	}
 	tmp = min(a[2], b[2]);
 	a[2] -= tmp;
 	b[2] -= tmp;

	tmp = min(a[2], b[0]);
 	a[2] -= tmp;
 	b[0] -= tmp;

 	tmp = min(a[1], b[1]);
 	a[1] -= tmp;
 	b[1] -= tmp;

 	tmp = min(a[1], b[0]);
 	a[1] -= tmp;
 	b[0] -= tmp;

 	tmp = min(a[0], b[2]);
 	a[0] -= tmp;
 	b[2] -= tmp;

 	tmp = min(a[0], b[1]);
 	a[0] -= tmp;
 	b[1] -= tmp;

 	tmp = min(a[0], b[0]);
 	a[0] -= tmp;
 	b[0] -= tmp;

 	tmp = min(a[1], b[2]);
 	a[1] -= tmp;
 	b[2] -= tmp;
 	ans -= 2 * tmp;
 	cout << ans << endl;
}

main() {
	bst;
	int t = 1;
	cin >> t;
	while(t--) {
		solve();
	}
}