f = open("text.in")
s = f.read()
f.close()


for i in range(len(s)):
    if not ('a' <= s[i] <= 'z' or 'A' <= s[i] <= 'A'):
        s[i] = " "

g = open("text.out", "w")

s = s.split()
suma = 0
cnt = len(s)

for cuv in s:
    suma += len(cuv)

g.write(str(suma // cnt))
g.close()