#!/bin/python3

import sys

def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    req1 = 1
    req2 = 1
    req3 = 1
    req4 = 1
    for i in password:
        if(ord(i) >= 97 and ord(i) <= 122):
            if(req1):
                req1 = 0
        elif(ord(i) >= 65 and ord(i) <= 90):
            if(req2):
                req2 = 0
        elif(i in '!@#$%^&*()-+'):
            if(req3):
                req3 = 0
        elif(ord(i) >= 48 and ord(i) <= 57):
            if(req4):
                req4 = 0
        
    summ = req1 + req2 + req3 + req4
    if(n < 6):
        return (max(abs(n - 6), summ))
    else:
        return (summ)
    
if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)