Both R1 and R2 run EIGRP. now there is the prefix 172.16.(1~255).0/24,and the summary prefix 172.16.0.0/16 coming into R1,
Here has a problem: they require only can use "PERMIT" and named ACL at R1's interface which links to R2 to deny the prefix 172.16.10.0/24 into the R2.
what shall i do?