Counting Sheep and Chickens by Heads and Legs

In a pasture, there are sheep and chickens grazing. Together, the sheep and chickens have a total of 36 heads and 100 legs. Let $s$ represent the number of sheep and $c$ represent the number of chickens.

We can express the situation with the following equations:

1. The total number of heads: $s + c = 36$

2. The total number of legs: $4s + 2c = 100$

How many sheep and how many chickens are there?