0. Introduction
1. Integer
2. Float & Complex
3. String
4. String Formatting
5. Boolean
6. Function
7. Struct
8. Method
9. Pointer
10. Closure
11. 조건문: If, else if, else
12. 반복문: for, break, continue
13. switch문
14. Interface
15. Array과 Slice
16. Queue와 Stack
17. Map
18. AVL_tree
19. Cosmos-SDK의 IAVL 트리