Gantt list: Process[1](0,1), Process[1](1,2), Process[2](2,3), Process[1](3,4), Process[2](4,5), Process[3](5,6), Process[2](6,7), Process[4](7,8), Process[3](8,9), Process[2](9,10), Process[5](10,11), Process[4](11,12), Process[3](12,13), Process[2](13,14), Process[5](14,15), Process[4](15,16), Process[3](16,17), Process[2](17,18), Process[4](18,19), Process[4](19,20)