depth = 0
forw = 0

for s in open("input.txt", 'r').read().splitlines():
	split = s.split()	
	match split[0]:
		case "forward":
			forw += int(split[1])
		case "down":
			depth += int(split[1])
		case "up":
			depth -= int(split[1])

print(depth*forw)