#!/bin/python3

import sys

def minimumNumber(n, password):
    N="0123456789"
    L="abcdefghijklmnopqrstuvwxyz"
    U="ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    S="!@#$%^&*()-+"
    s=4
    for a in N:
        if a in password:
            s-=1
            break
    for a in L:
        if a in password:
            s-=1
            break
    for a in U:
        if a in password:
            s-=1
            break
    for a in S:
        if a in password:
            s-=1
            break    
    if n>=6 and s==0:
         return 0
    elif n>=6:
        return s
    else:
        return max(6-n,s)

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