GATE Computer Science (CS) 2016 Shift 2 Solved Paper

Let A₁, A₂, A₃, and A₄ be four matrices of dimensions 10 × 5, 5 × 20, 20 × 10, and 10 × 5, respectively. The minimum number of scalar multiplications required to find the product A₁A₂A₃A₄ using the basic matrix multiplication method is ______.