I have two list my requirement is I want to create one list whose data should be all value of x minus all value from y.

For example.

```
List<string> s = new List<string>();
List<string> y = new List<string>();

List s contain {“a”,”b”,”c”,”d”}
List y contain {“b”,”c”}

```

I want one to create one more list 

```
List<string>  z = new List<string>();

```

Whose value should be 

```
{“a”,”d”}

```