n = int(input())
string = input()
count_sm = 0
count_bi = 0
count_sym = 0
count_num = 0
for i in range(0,n):
    ch = string[i]
    if ch.islower():
        count_sm += 1
    if ch.isupper():
        count_bi += 1
    elif ch.isnumeric():
        count_num += 1
    elif ch in ['!','@','#','$','%','^','&','*',')','()','-','+']:
        count_sym += 1
val = 0
if count_sm == 0:
   # print('here1')
    val+=1
if count_bi == 0:
   # print('here2')
    val+=1
if count_num == 0:
    #print('here3')
    val+=1
if count_sym == 0:
    #print('here4')
    val+=1
if val + n < 6:
    print(6 - n)
else:
    print(val)