#!/bin/python3

import sys

def minimumNumber(n, password):
    
    special = "!@#$%^&*()-+"
    x=0
    if n<6:
        if  not any(c.isdigit()  for c in password):
            x=x+1
        if  not any(c.islower()  for c in password):
            x=x+1
        if  not any(c.isupper()  for c in password):
            x=x+1
        if  not any(c in special for c in password):
            x=x+1
        if x>6-n:
            return x
        else:
            return (6-n)
    if n>=6:
        if not any(c.isdigit()  for c in password):
            x=x+1
        if not any(c.islower()  for c in password):
            x=x+1
        if not any(c.isupper()  for c in password):
            x=x+1
        if not any(c in special for c in password):
            x=x+1
        return x
                    
            
        

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