You will be given an array A[ ] of positive integers, the task is to find the left most digit of the product of the numbers in this array.
The first line of input contains a single integer T denoting the number of test cases.Then T test cases follow. The first line of each test case consists of N, the size of the array. In the next line are N space separated positive integers which are in array A[ ].
Corresponding to each test case, in a new line, print the left most digit of the product of the numbers in the array A[ ].
1 ≤ T ≤ 100
1 ≤ N ≤ 100
1 ≤ A[i] ≤ 1010