#!/bin/python3

import sys

def minimumNumber(n, password):
    c=n
    d=0
    e=0
    f=0
    g=0
    z='!@#$%^&*()-+'
    
    for i in password:
        if i.islower():
            d=1
        if i.isupper():
            e=1
        if i.isnumeric():
            f=1
        if i in z:
            g=1
    x=4-d-e-f-g
    c=c+x
    if c<6:
        return 6-c+x
    else:
        return x
    # 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)