#!/bin/python3

import sys

length = 6
numbers = "0123456789"
lower_case = "abcdefghijklmnopqrstuvwxyz"
upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
special_characters = "!@#$%^&*()-+"


def minimumNumber(n, password):
    edits = 0
    a =set(numbers)
    b =set(lower_case)
    c =set(upper_case)
    d =set(special_characters)
    
    p =set(password)
    
    if a.intersection(p):
        pass
    else:
        edits +=1       
    if b.intersection(p):
        pass
    else:
        edits +=1         
    if c.intersection(p):
        pass
    else:
        edits +=1  
    if d.intersection(p):
        pass
    else:
        edits +=1 
        
    additional = 0 
    if (n + edits ) < 6:
        additional = 6 - (len(password) + edits)
        edits += additional
    
    return edits
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)