#!/bin/python3

import sys
def has_common_chars(s1, s2):
    return len(set(s1) & set(s2)) > 0
def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    checks = 4
    sc = '!@#$%^&*()-+'
    s = password
    if (any(x.isupper() for x in s)):
        checks -= 1
    if (any(x.islower() for x in s)):
        checks -= 1
    if (any(x.isdigit() for x in s)):
        checks -= 1
    if (has_common_chars(s,sc)>0):
        checks -= 1
    if ((checks + len(s))<6):
        checks = checks + (6 - len(s) - checks)
    return checks
    

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