from sys import stdin

def judge(filename, currYear):
    f = stdin
    n = int(f.readline())
    for i in range(n):
        Y = {}
        m = int(f.readline())
        for j in range(m):
            years = str.split(f.readline())
            start = int(years[0])
            stop = int(years[1] if len(years) > 1 else currYear)
            for k in range(start, stop+1):
                if k not in Y: Y[k] = 0
                Y[k] += 1
        x = max(Y.values())
        print sorted([y[0] for y in Y.items() if y[1] == x])

judge("judge.txt", 2015)