length = int(raw_input())
password = list(raw_input())
flg_list=[0,0,0,0]
count=0
for i in range(0,len(password)):
    temp = ord(password[i])
    if 47 < temp < 58:
        flg_list[0] += 1
    elif 96 < temp < 123:
        flg_list[1] += 1
    elif 64 < temp < 92:
        flg_list[2] += 1
    elif temp == 33 or 34<temp<39 or 39<temp<44 or temp == 45 or temp == 64 or temp == 94:
        flg_list[3] += 1
for i in range(0,len(flg_list)):
    if flg_list[i] == 0:
        count += 1

if count+length < 6:
    print 6-length
else:
    print count