n=int(input())
s=input()
n=len(s)
st="!@#$%^&*()-+"
a=0
b=0
c=0
d=0
e=0
for i in s:
    if(i.isdigit()):
        a=a+1
    elif(i.islower()):
        b=b+1
    elif(i.isupper()):
        c=c+1
    elif(i in st):
        d=d+1
x=0
ans=0
if(a!=0):
    x=x+1
if(b!=0):
    x=x+1
if(c!=0):
    x=x+1
if(d!=0):
    x=x+1
if(x!=4):
    ans=4-x
if(n>=6):
    print(ans)
elif(ans+n<6):
    print(6-n)
elif(ans+n>=6):
    print(ans)