Minimum Tables

You are given a series of test cases. For each test case, you are provided with a number of groups of guests, where each group has a size of either 1, 2, 3, or 4. Your task is to determine the minimum number of tables required to seat all guests, given that each table seats exactly $4$ guests and every guest must be seated at one table.

Note: You may need to combine different groups to fill a table optimally. For example, a group of 3 can be paired with a group of 1. Use a greedy approach to pair and partition the groups optimally.

inputFormat

The input is read from standard input (stdin) and is structured as follows:

• The first line contains an integer T, the number of test cases.
• For each test case, the first line contains an integer n, representing the number of groups.
• The second line contains n space-separated integers, each indicating the size of a group.

Constraints: Group sizes will be one of these values: 1, 2, 3, or 4.

outputFormat

For each test case, output a single integer on a separate line: the minimum number of tables required to seat all groups.

## sample

2
5
1 2 3 4 2
3
2 2 2

3
2

</p>