Suppose there are 4 memory blocks, B1, B2, B3, and B4, with sizes of 30K, 15K, 50K, and 20K, respectively. And we have 4 processes, P1, P2, P3, and P4, with corresponding request sizes of 15K, 20K, 20K, and 50K. What is the algorithm for all processes to be allocated memory?