1994E - Wooden Game - CodeForces Solution

import math
import sys
from collections import defaultdict,Counter
from bisect import bisect_left,bisect_right
from heapq import heappush,heappop,heapify
import gc
 
sys.setrecursionlimit(20000)
 
def getList(val=0):     if not val:return list(map(int,input().split()))
    else:return list(map(str,input().split()))
def getTuple(val=0):
    if not val:return map(int,input().split())
    return map(str,input().split())
def printList(arr,pri=False):
    if pri:print('ans',end=' ')
    for i in arr:print(i,end=' ')
    print()


def myCode():
    n = int(input())
    ans = []
    arr = [0 for i in range(20)]
    for __ in range(n):
        count = int(input())
        ddd = getList()
        ind = 0
        while count:
            b = count%2
            count = count>>1
            if b:arr[ind]+=1
            ind+=1
        for i in range(19,-1,-1):
        if arr[i]>1:
            ans += ['1']*(i+1)
            break
        elif arr[i]==1:
            ans.append('1')
        else:ans.append('0')
    print(int(''.join(ans),2))

        
for _ in range(int(input())):
    myCode()