#!/bin/python3

import sys

def minimumNumber(n, password):
    l=[0,0,0,0]
    for c1 in "0123456789":
        if c1 in password:
            l[0]=1
            break
    for c2 in "abcdefghijklmnopqrstuvwxyz":
        if c2 in password:
            l[1]=1
            break
    for c3 in "ABCDEFGHIJKLMNOPQRSTUVWXYZ":
        if c3 in password:
            l[2]=1
            break
    for c4 in "!@#$%^&*()-+":
        if c4 in password:
            l[3]=1
            break
    d=4-sum(l)        
    if n+d>=6:
        return d
    else:
        return 6-(n+d)+d

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