numbers = "0123456789"
lower_case = "abcdefghijklmnopqrstuvwxyz"
upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
special_characters = "!@#$%^&*()-+"
t=int(input())
il=input()
cnt=0
for i in il:
    if i in numbers:
        cnt+=1
        break
for i in il:
    if i in lower_case:
        cnt+=1
        break
for i in il:
    if i in upper_case:
        cnt+=1
        break
for i in il:
    if i in special_characters:
        cnt+=1
        break
print(max(4-cnt,6-t))