# A jupyter notebook is composed by one or more cells.
# A cell is used to write and execute your codes.
# A cell is also used to write descriptions, notes, formulas, etc.
# You can format your descriptions by using HTML or LaTex codes.
# During this tutorial, you are expected to write only python codes.
# Interested readers may also use HTML and LaTex, but it is not necesary to complete this tutorial. 

#
# We explain basic usage of cells in Jupyter notebooks here
#

# This is the first cell in this notebook.
# You can write Python code here, 
# and then EXECUTE/RUN it by
# 1) pressing SHIFT+ENTER
# 2) clicking "Run" on the menu


# here is a few lines of python codes

print("hello world")
str="*"
for i in range(5):
    print(str)
    str+="*"

# after executing this cell, you will see the outcomes immedeately after this cell
#     you may change the range above and re-run this cell

# after executing this cell, you can continue with the next cell

# This is the second cell.
#
# When you double click after the last cell, a new cell appears automatically.
#     It automatically happens when you execute the last cell as well. 
#
# By using menu item "Insert", you may also add a new cell before or after the selected cell.
#     When a cell is selected, you may delete it by using menu item "Edit".
#
# As you may notice, there are other editing options under "Edit",
#     for example, copy/cut-paste cells and split-merge cells.