Table : Execution time (seconds) for selected MF of natural products on a compute-optimized c2-standard-4 Google cloud VM. Times for MOLGEN 5.0 were determined with the -noaromaticity flag to achieve comparability. Both MOLGEN and surge were instructed to generate but not to output structures. For randomly selected 10 molecular formulae, 4 options of surge were tested and results are given in Table . These options are -p0:1 At most one cycle of length 5 -P