n=int(input())
s=input()
special="!@#$%^&*()-+"
numbers = "0123456789"
if(n<6):
  req=6-n
else:
  req=0
f=0
ans=0
for i in s:
  if(i.isupper()):
    f=1
    break
if(f==0):
  ans+=1
else:
  f=0
for i in s:
  if(i.islower()):
    f=1
    break
if(f==0):
  ans+=1
else:
  f=0
for i in s:
  if(i in numbers):
    f=1
    break
if(f==0):
  ans+=1
else:
  f=0
for i in s:
  if(i in special):
    f=1
    break
if(f==0):
  ans+=1
else:
  f=0
print(max(ans,req))