# f = open("data.txt",'w')
# f.write("hello world")
# f.close()

# f = open("data.txt",'r')
# file= f.read()
# print(file)
# f.close()


# f = open("data.txt",'a')
# f.write("HELLO USER\n")
# f.close()

# 'w' = writing
# 'r' = reading
# 'a' = appending