Can someone explain what this pseudo code is doing and math needed to get the expected value.

Let rand(a,b) return an integer uniformly at random from the range [a, b]. Each call to rand(a,b) is independent. Consider the following function: f(k, n): if ks1 return rand(1, n) return 2 fs,n 2' What is the Expected value of f k, n), assume k is a power of 2. Please show your work. Beside the mathematical work, am expect 1-2 sentence that explain what the above pseudo code does and why your derivation is the right thing to do