n=int(input())
s=input().strip()
cnt=0
di=1
lo=1
up=1
sp=1
sp_l=[]
s2='!@#$%^&*()-+'
for i in s2:
    sp_l.append(i)
    
for i in s:
    cnt+=1
    if(i.islower()):
        lo=0
    elif(i.isupper()):
        up=0
    elif(i.isdigit()):
        di=0
    elif(i in sp_l):
        sp=0
        
dane=lo+up+di+sp        
if(cnt>=6):
    print(dane)
else:
    ans=max(dane,6-cnt)
    print(ans)