Remove extra brackets in a mathematical expression: i.e. for Given input: ((A+B)*C), expected output is (A+B)*C

Question

Can someone please write a C program to reverse "N" nodes of list. In the above question N= 3.
Program should be generic so it can work for any value assigned to N.

Input List => 1 2 3 4 5 6 7 8 9 10 11
Output List => 3 2 1 6 5 4 9 8 7 10 11
for N=3

Input List => 1 2 3 4 5 6 7 8 9 10 11
Output List => 4 3 2 1 8 7 6 5 9 10 11
for n=4