#include<bits/stdc++.h>
using namespace std ;
#define pb push_back
#define mp make_pair
#define infile() freopen("large.in","r",stdin);
#define output() freopen("output.txt","w",stdout);
#define ll long long
#define sc(t); scanf("%d",&t);
#define scl(t); scanf("%lld",&t);
#define sc2(n,m); scanf("%d%d",&n,&m);
#define scl2(n,m); scanf("%lld%lld",&n,&m);
#define debug(); printf("tushar\n");
#define N 105
#define mod 1000000007
#define printi(n) printf("%d",n);
#define inf ((1<<29)-1)
#define linf ((1LL<<60)-1)
const double eps = 1e-9;
set < ll > s ;
set < ll > :: iterator it ;
vector < ll > v ;
int n,m,q ;
char a[N] ;
int main()
{
int i , j , t ;
sc(n) ; 
scanf("%s",a) ; 
string numbers,lower,special, upper ; 
numbers = "0123456789" ; 
lower = "abcdefghijklmnopqrstuvwxyz" ; 
upper = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" ; 
special = "!@#$%^&*()-+" ; 

int x,y,z,w; 
x=0;
y=0;
z=0;
w=0;
for(i = 0 ; i < numbers.length(); i++ )
{
	for(j =  0 ; j < n ; j++ )
	{
		if(numbers[i] == a[j])
		x=1;
	}
}

for(i = 0 ; i < lower.length(); i++ )
{
	for(j =  0 ; j < n ; j++ )
	{
		if(lower[i] == a[j])
		y=1;
	}
}

for(i = 0 ; i < upper.length(); i++ )
{
	for(j =  0 ; j < n ; j++ )
	{
		if(upper[i] == a[j])
		z=1;
	}
}

for(i = 0 ; i < special.length(); i++ )
{
	for(j =  0 ; j < n ; j++ )
	{
		if(special[i] == a[j])
		w=1;
	}
}

int ans = 0 ; 
//printf("x = %d\n",x) ; 
if(x == 0)
{
	ans++ ; 
	n++ ; 
}

if(y == 0)
{
	ans++ ; 
	n++ ; 
}

if(z == 0)
{
	ans++ ; 
	n++ ; 
}

if(w == 0)
{
	ans++ ;
	n++ ; 
}

printf("%d\n",ans+max(0,6-n)) ; 
return 0 ;
}