initproblem 1
subproblem 1 solver euler
subproblem 1 solver rk2
subproblem 1 solver rk2heun
subproblem 1 solver rk4
subproblem 1 solver rkf54
subproblem 1 solver rkf54m
subproblem 1 solver rkf54s
subproblem 2 solver euler
subproblem 2 solver rk2
subproblem 2 solver rk2heun
subproblem 2 solver rk4
subproblem 2 solver rkf54
subproblem 2 solver rkf54m
subproblem 2 solver rkf54s
