debug = False

def do_homework(filename: str):
	# Read file as list of strings
	with open(filename, "r") as fp:
		data = fp.read().splitlines()

	# Gimme the operators
	last_row = data[-1]
	operators = last_row.split()

	# Use that to find the lengths
	num_of_cols = len(operators)

	icol_prev = 0
	final_result = 0
	for icol in range(num_of_cols):
		op = operators[icol]

		# Find the length of this column.
		col_len = len(last_row[icol_prev:]) - len(last_row[icol_prev + 1:].lstrip())
		
		# Do the math
		if op == '*':
			result = 1
			if debug:
				print(1, end="")
			for row in data[:-1]:
				num = int(row[icol_prev:icol_prev + col_len])
				if debug:
					print(f" * {num}", end="")

				result *= num
		elif op == '+':
			result = 0
			if debug:
				print(0, end="")
			for row in data[:-1]:
				num = int(row[icol_prev:icol_prev + col_len])
				if debug:
					print(f" + {num}", end="")

				result += num
		else:
			assert False, "fuck this"
		
		icol_prev += col_len
		final_result += result
		if debug:
			print(f" = {result}")
	return final_result

if __name__ == "__main__":
	assert do_homework("testinput") == 4277556

	print(do_homework("input"))