#!/bin/python3

import sys

def minimumNumber(n, password):
    cl=['!','@','#','$','%','^','&','*','(',')','-','+']
    l=0
    d=0
    l=0
    u=0
    c=0
    cnt=0
    sol=0
    
    if(n<=2):
        return 6-n
    for i in range (len(password)):
        x=password[i]
        if(ord(x)-ord('0')<10 and d==0 and ord(x)-ord('0')>=0):
            d=1
        if(ord(x)-ord('a')<26 and l==0 and ord(x)-ord('a')>=0):
            l=1
        if(ord(x)-ord('A')<=26 and u==0 and ord(x)-ord('A')>=0):
            u=1
        if x in cl and c==0:
            c=1
    if l==0:
        sol=sol+1
    if u==0:
        sol+=1
    if c==0:
        sol+=1
    if d==0:
        sol+=1
    tem=len(password)+sol
    if(tem<6):
        return sol+6-tem
    return sol
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    # Return the minimum number of characters to make the password strong

if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)