50.83%

Write a program to print sum of an AP with n terms with first term a and common difference d.

**Input: **

The first line of the input contains T denoting the number of testcases. The first line of the test case will be the number of terms of AP and second line its first term and common difference.

**Output:**

For each test case, output will be the sum of AP

**Constraints:**

1 <= T<= 100

1 <= N <= 1000

1 <= a,d <= 100

**Example:**

Input:

1

5

1 3

Output:

35