#!/bin/python

import sys
import re

def minimumNumber(n, password):
    if(n>=1 and n<=100):
 
     count=0   
     extra=0
        if(n>=6):
            extra=0
        else:
            extra=6-n
        if (re.match("[A-Z]",password)):
            count =count
        else:
            count=count+1
        
        if (re.match("[a-z]",password)):
            count =count
        else:
            count=count+1
        
        if (re.match("[0-9]",password)):
            count =count
        else:
            count=count+1
        
        if ('!'or '@' or '#' or '$' or '%' or '^' or '&' or '*' or '(' or')' or '+' or '-') in password :
            count =count
        else:
            count=count+1
        
        if extra>count:
            return extra
        else:
            return count
        
    
    # Return the minimum number of characters to make the password strong

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