cases = int(input())
for case in range(cases):
    n = int(input())
    a = [int(i) for i in input().split()]
    x,y = -1,-2
    c = 0 
    while y >= - len(a):
        if a[y] < a[x]:
            a[y], a[x] = a[x], a[y]
            c += 1
            break
        else:
            x -= 1
            y -= 1
    if c > 0:
        if a[x+1] > a[x]:
            temp = a[x + 1]
            a.remove(a[x + 1])
            a.append(temp)
        else:
            temp = a[x]
            a.remove(a[x])
            a.append(temp)
 
        s = [str(i) for i in a]
        res = int("".join(s))
        print(res)
    else:
        print(-1)

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Mgo1CjEgNSA0IDggMwoxMAoxIDQgNyA0IDUgOCA0IDEgMiA2

2
5
1 5 4 8 3
10
1 4 7 4 5 8 4 1 2 6