n = int(input().strip())
password = input().strip()
ans = 4
for i in "!@#$%^&*()-+":
    if i in password:
        ans-=1
        break
for i in "abcdefghijklmnopqrstuvwxyz":
    if i in password:
        ans-=1
        break
for i in "abcdefghijklmnopqrstuvwxyz":
    if i.upper() in password:
        ans-=1
        break        
for i in "1234567890":
    if i in password:
        ans-=1
        break
print(ans+ max(0,6 - n - ans))