#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    values=[False,False,False,False,False]
    total=0
    if(len(password)>=6):
        values[0]=True
    for i in password :
        if i in "0123456789" :
            values[1]=True
        if i in "abcdefghijklmnopqrstuvwxyz" :
            values[2]=True
        if i in "ABCDEFGHIJKLMNOPQRSTUVWXYZ" :
            values[3]=True
        if i in "!@#$%^&*()-+" :
            values[4]=True
    for i in values[1:] :
            if(i==False) :
                total+=1
    if(values[0]==True) :
        return total
    else :
        return max(total,6-len(password))        
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)