splitting.monotonic: slightly faster.
splitting.monotonic: slightly faster.

mrjbq7/factor,tgunr/factor,mrjbq7/factor,tgunr/factor,mrjbq7/factor,mrjbq7/factor,tgunr/factor,tgunr/factor,factor/factor,factor/factor,factor/factor,factor/factor,factor/factor,mrjbq7/factor,factor/factor,tgunr/factor,mrjbq7/factor,tgunr/factor