#!/bin/python3

import sys

def minimumNumber(n, a):
    # Return the minimum number of characters to make the password strong
    e=1
    f=1
    g=1
    h=1
    b="!@#$%^&*()-+"
    c="0123456789"
    if n>=6:
        for i in a:
            if ord(i)<=90 and ord(i)>=65:
                e=0
            elif ord(i)<=122 and ord(i)>=97:
                f=0
            elif i in b:
                g=0
            elif i in c:
                h=0
            if e==1 and f==1 and g==1 and h==1:
                break
        return e+f+g+h
    elif n>2:
        for i in a:
            if ord(i)<=90 and ord(i)>=65:
                e=0
            elif ord(i)<=122 and ord(i)>=97:
                f=0
            elif i in b:
                g=0
            elif i in c:
                h=0
            if e==1 and f==1 and g==1 and h==1:
                break
        return max(6-n,e+f+g+h)
    else:
        return 6-n
        
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)