Given an array Arr of N numbers. You need to write a program to find the first digit of product of these N integers.
First line of input contains an integer T which denotes the number of test cases. Then T test cases follows. First line of each test case contains a single integer N which denotes the number of elements in the array. Second line of each test case contains N space separated integers which denotes the elements of the array.
For each test case, in a new line print the first digit of product of these N integers present in the array.
5 8 3 7
6 7 9