def main():
    ct = int(input())

    for i in range(ct):
        input()
        a = [int(b) for b in input().split()]
        
        b = {}
        for c in a:
            if c not in b:
                b[c] = 0
            b[c] += 1

        d = [(e, b[e]) for e in b]

        d.sort(key=lambda x: x[1], reverse=True)

        oth = len(a)-d[0][1]

        print(max(d[0][1] - oth, len(a)%2))



main()