Legs on a Farm

After a long and fulfilling career, Chef has decided to retire to a farm out in the countryside. This farm has several cows and chickens, but Chef doesn't know exactly how many of each there are — he can only see that there are $N$ legs in total across all the animals. Note that each cow has $4$ legs and each chicken has $2$ legs, and it is guaranteed that $N$ is even. With $N$ legs in total,