var = input("digite a letra: ").upper()

i = 0
e = 0
d = 0
g = 0
h = 0
while	(var != "x"):
	if(var == "v"):
		i = i + 3
		
	elif(var == "e"):
		e = e + 2
		
	elif(var == "d"):
		d = d + 1
		
	
	g = g + 1
	
h = g*3/100
print(round(h, 2))