diff --git a/calc.py b/calc.py
new file mode 100644
index 0000000..36e7b30
--- /dev/null
+++ b/calc.py
@@ -0,0 +1,117 @@
+NUMBER_TOKEN = 0
+PLUS_TOKEN = 1
+MINUS_TOKEN = 2
+TIMES_TOKEN = 3
+DIVIDE_TOKEN = 4
+LEFT_BRACKET_TOKEN = 5
+RIGHT_BRACKET_TOKEN = 6
+WHITESPACE_TOKEN = 7
+EOF_TOKEN = 8
+
+program = input("Please enter an expression to evaluate: ")
+tokens = []
+
+i = 0
+while i < len(program):
+	if program[i].isdigit():
+		tmp_number = 0
+		while i < len(program) and program[i].isdigit() :
+			tmp_number *= 10
+			tmp_number += ord(program[i]) % 48
+			i += 1
+		tokens.append([NUMBER_TOKEN, tmp_number])
+		i -= 1
+	elif program[i] == "+":
+		tokens.append([PLUS_TOKEN])
+	elif program[i] == "-":
+		tokens.append([MINUS_TOKEN])
+	elif program[i] == "*":
+		tokens.append([TIMES_TOKEN])
+	elif program[i] == "/":
+		tokens.append([DIVIDE_TOKEN])
+	elif program[i] == "(":
+		tokens.append([LEFT_BRACKET_TOKEN])
+	elif program[i] == ")":
+		tokens.append([RIGHT_BRACKET_TOKEN])
+	elif program[i] == " ":
+		tokens.append([WHITESPACE_TOKEN])
+	else:
+		print("Invalid charatcer: " + i)
+	i += 1
+tokens.append([EOF_TOKEN])
+
+ast = []
+NUMBER_AST = 0
+PLUS_AST = 1
+MINUS_AST = 2
+TIMES_AST = 3
+DIVIDE_AST = 4
+NEGATE_AST = 5
+
+index = 0
+
+def current ():
+	return tokens[index][0]
+
+def eat(token):
+	global index
+	if current() == token:
+		index += 1
+	else:
+		print("Invalid token")
+
+def eat_whitespace():
+	while current() == WHITESPACE_TOKEN:
+		eat (WHITESPACE_TOKEN)
+
+def factor():
+	node = []
+	eat_whitespace()
+	if current() == NUMBER_TOKEN:
+		node = [NUMBER_AST, tokens[index][1]]
+		eat (NUMBER_TOKEN)
+	elif current() == LEFT_BRACKET_TOKEN:
+		eat (LEFT_BRACKET_TOKEN)
+		node = expr()
+		eat (RIGHT_BRACKET_TOKEN)
+	else:
+		eat (MINUS_TOKEN)
+		node = [NEGATE_AST, factor()]
+	eat_whitespace()
+	return node
+def term():
+	node = factor()
+	while current() in [TIMES_TOKEN, DIVIDE_TOKEN]:
+		if current () == TIMES_TOKEN:
+			eat (TIMES_TOKEN)
+			node = [TIMES_AST, node, factor()]
+		else:
+			eat (DIVIDE_TOKEN)
+			node = [DIVIDE_AST, node, factor()]
+	return node
+def expr():
+	node = term()
+	while current() in [PLUS_TOKEN, MINUS_TOKEN]:
+		if current() == PLUS_TOKEN:
+			eat (PLUS_TOKEN)
+			node = [PLUS_AST, node, term()]
+		else:
+			eat (MINUS_TOKEN)
+			node = [MINUS_AST, node, term()]
+	return node
+
+def interpret (ast):
+	if ast[0] == NUMBER_AST:
+		return ast[1]
+	elif ast[0] == PLUS_AST:
+		return interpret(ast[1]) + interpret(ast[2])
+	elif ast[0] == MINUS_AST:
+		return interpret(ast[1]) - interpret(ast[2])
+	elif ast[0] == TIMES_AST:
+		return interpret(ast[1]) * interpret(ast[2])
+	elif ast[0] == DIVIDE_AST:
+		return interpret(ast[1]) / interpret(ast[2])
+	elif ast[0] == NEGATE_AST:
+		return -interpret(ast[1])
+
+print("Your answer: " + str(interpret(expr())))
diff --git a/cipher.py b/cipher.py
new file mode 100644
index 0000000..0ed509d
--- /dev/null
+++ b/cipher.py
@@ -0,0 +1,29 @@
+print ("Welcome to bybb's Python Caesar Cipher Program!")
+option = input("Do you want to? 'encode' or 'decode'")
+while not option in ["encode", "decode"]:
+	option = input("Do you want to? 'encode' or 'decode'")
+
+cipher_text = input("Cipher Text: ")
+rot = int(input("Rotation Amount: "))
+
+ciphered_string = ""
+
+if option == "encode":
+	for i in cipher_text:
+		if i.isalpha():
+			if ord(i) > 90:
+				ciphered_string = ciphered_string + chr(((ord(i) % 97 + rot) % 26) + 97)
+			else:
+				ciphered_string = ciphered_string + chr(((ord(i) % 65 + rot) % 26) + 65)
+		else:
+			ciphered_string = ciphered_string + i
+else:
+	for i in cipher_text:
+		if i.isalpha():
+			if ord(i) > 90:
+				ciphered_string = ciphered_string + chr(((ord(i) % 97 - rot) % 26) + 97)
+			else:
+				ciphered_string = ciphered_string + chr(((ord(i) % 65 - rot) % 26) + 65)
+		else:
+			ciphered_string = ciphered_string + i
+print("Your ciphered string is: " + ciphered_string)
\ No newline at end of file
diff --git a/options.py b/options.py
new file mode 100644
index 0000000..b58979a
--- /dev/null
+++ b/options.py
@@ -0,0 +1,5 @@
+x = input("Your options are: add / subtract")
+while not x in ["add", "subtract"]:
+	x = input("Your options are: add / subtract")
+
+print("You chose: " + x[0])
\ No newline at end of file
diff --git a/test.py b/test.py
new file mode 100644
index 0000000..e511247
--- /dev/null
+++ b/test.py
@@ -0,0 +1 @@
+print("Hello, World")
diff --git a/test2.py b/test2.py
new file mode 100644
index 0000000..644c3ba
--- /dev/null
+++ b/test2.py
@@ -0,0 +1,20 @@
+var = 0
+def outer():
+	global var
+	var = 1
+	def inner():
+		global var
+		var = 2
+		print("inner:", str(var))
+	inner()
+	print("outer:", str(var))
+outer()
+print("main:", str(var))
+
+var = 5
+def a():
+	def b():
+		return var
+	return b()
+
+print(str(a()))
\ No newline at end of file