#!/bin/python3

import sys

numbers = "0123456789"
lower = "abcdefghijklmnopqrstuvwxyz"
upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
special = "!@#$%^&*()-+"

def minimumNumber(n, password):
    conditions = [1, 2, 3, 4]
    for index, value in enumerate(password):
        if value in numbers:
            try:
                conditions.remove(1)
            except ValueError:
                pass
        if value in lower:
            try:
                conditions.remove(2)
            except ValueError:
                pass
        if value in upper:
            try:
                conditions.remove(3)
            except ValueError:
                pass
        if value in special:
            try:
                conditions.remove(4)
            except ValueError:
                pass
    result = len(conditions)
    current_length = len(password) + len(conditions)
    required_length = 6
    difference = required_length - current_length
    if difference > 0:
        result += difference
    
    
    
    return (result)
    # 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)