n = int(input())
s = input()

a = 0 if sum(1 for x in s if '0' <= x <= '9') else 1
a += 0 if sum(1 for x in s if 'a' <= x <= 'z') else 1
a += 0 if sum(1 for x in s if 'A' <= x <= 'Z') else 1
a += 0 if sum(1 for x in s if x in '!@#$%^&*()-+') else 1

print(max(a, 6 - n))