Basically, you are in a call with your interviewer (or potentially in person, depending on the stage). They will present you with a question, and you must talk your way through the solving process.

You are given a 0-indexed integer array strength, where strength[i] denotes the strength of the ith wizard.

For a contiguous group of wizards (i.e., the wizards' strengths form a subarray of strength), the total strength is defined as the product of the following two values:

• The strength of the weakest wizard in the group.
• The sum of all the individual strengths of the wizards in the group.

Return the sum of the total strengths of all contiguous groups of wizards. Since the answer may be very large, return it modulo 10^9 + 7.