private static void Main()
{
int remainingTestCases = FastIO.ReadNonNegativeInt();
while (remainingTestCases-- > 0)
{
int digitCount = FastIO.ReadNonNegativeInt();
int[] digits = new int[digitCount];
for (int d = 0; d < digitCount; ++d)
{
digits[d] = FastIO.ReadNonNegativeInt();
}
if (JNEXT.Solve(digitCount, digits))
{
for (int d = 0; d < digitCount; ++d)
{
FastIO.WriteDigit(digits[d]);
}
}
else
{
FastIO.WriteNegativeOne();
}
FastIO.WriteLine();
}
FastIO.Flush();
}