Given a value V. You have to make change for V cents, given that you have infinite supply of each of C{ C1, C2, .. , Cm} valued coins. Find the minimum number of coins to make the change.

Input:
The first line of input contains an integer T denoting the number of test cases. The first line of each test case is V and N, V is the value of cents and N is the number of coins. The second line of each test case contains N input C[i], value of available coins.

Output:
Print the minimum number of coins to make the change, if not possible print "-1".

Constraints:
1 ≤ T ≤ 100
1 ≤ V ≤ 10⁶
1 ≤ N ≤ 10⁶
1 ≤ C[i] ≤ 10⁶

Example:
Input:
1
7 2
2 1

Output:
4

Explanation :
Testcase 1: We can use coin with value 2 three times, and coin with value 1 one times to change a total of 7.

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