import re

# Fill Input

try:
	with open("07.txt", 'r', encoding='utf-8') as file:
		input = file.read()
except Exception as e:
	print(f"An error occurred: {e}")

# Result
def is_number(s:str):
	return ord('0')<= ord(s[0]) and ord(s[0]) <=ord('9')

dict = {}
for line in input.split('\n'):
	if re_match := re.search(r"([a-z]+|[0-9]+) ([A-Z]+) ([a-z]+|[0-9]+) -> ([a-z]+)", line):
		v1 = re_match.group(1)
		op = re_match.group(2)
		v2 = re_match.group(3)
		rs = re_match.group(4)
		dict[rs] = [op,v1,v2]
		continue

	if re_match := re.search(r"(NOT) ([a-z]+) -> ([a-z]+)", line):
		op = re_match.group(1)
		v1 = re_match.group(2)
		rs = re_match.group(3)
		dict[rs] = [op,v1,None]
		continue	


	if re_match := re.search(r"([a-z]+|[0-9]+) -> ([a-z]+)", line):
		v1 = re_match.group(1)
		rs = re_match.group(2)
		dict[rs] = [None,v1,None]
		continue

# Part B
#dict["b"]=[None,..., None]

to_dict = {}
while len(dict):
	for key in dict:
		v = dict[key]

		if not v[0] and (is_number(v[1]) or v[1] in to_dict):
			to_dict[key] = v

		if (is_number(v[1]) or v[1] in to_dict ) and (not v[2] or is_number(v[2]) or v[2] in to_dict):
			to_dict[key] = v

	
	for key in to_dict:
		if key in dict:
			dict.pop(key)




for key in to_dict:
	v = to_dict[key]

	if not v[0] and is_number(v[1]):
		to_dict[key] = int(v[1])
		continue

	if not v[0] and v[1] in to_dict:
		to_dict[key] = to_dict[v[1]]
		continue

	if v[0] == "NOT":
		to_dict[key] = ~to_dict[v[1]]
		continue
	
	if (v[1] in to_dict) and is_number(v[2]):
		match v[0]:
			case "LSHIFT":
				to_dict[key] = to_dict[v[1]] << int(v[2])
				continue
			case "RSHIFT":
				to_dict[key] = to_dict[v[1]] >> int(v[2])
				continue
			case "AND":
				to_dict[key] = to_dict[v[1]] & int(v[2])
				continue
			case "OR":
				to_dict[key] = to_dict[v[1]] | int(v[2])
				continue
	
	if is_number(v[1]) and (v[2] in to_dict):
		match v[0]:
			case "LSHIFT":
				to_dict[key] = int(v[1]) << to_dict[v[2]]
				continue
			case "RSHIFT":
				to_dict[key] = int(v[1]) >> to_dict[v[2]]
				continue
			case "AND":
				to_dict[key] = int(v[1]) & to_dict[v[2]]
				continue
			case "OR":
				to_dict[key] = int(v[1]) | to_dict[v[2]]
				continue
	
	if (v[1] in to_dict) and (v[2] in to_dict):
		match v[0]:
			case "LSHIFT":
				to_dict[key] = to_dict[v[1]] << to_dict[v[2]]
				continue
			case "RSHIFT":
				to_dict[key] = to_dict[v[1]] >> to_dict[v[2]]
				continue
			case "AND":
				to_dict[key] = to_dict[v[1]] & to_dict[v[2]]
				continue
			case "OR":
				to_dict[key] = to_dict[v[1]] | to_dict[v[2]]
				continue
	

print(to_dict["a"])