#include <bits/stdc++.h>
 
using namespace std;
 
#define SPEED ios::sync_with_stdio(false); cin.tie(0); cout.tie(0)
#define fileio freopen("in.in", "r", stdin),freopen("out.out", "w", stdout);
#define ll long long int
#define FF first
#define SS second
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define pll pair<long long int,long long int>
#define sd(x) scanf("%d",&x)
#define slld(x) scanf("%lld",&x)
#define pd(x) printf("%d\n",x)
#define plld(x) printf("%lld\n",x)
#define pss printf
#define MOD 1000000007
#define INF 1e18
#define eps 0.00001
#define endl '\n'
#define debug(n1) cout<<n1<<endl

string numbers = "0123456789";
string lower_case = "abcdefghijklmnopqrstuvwxyz";
string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string special_characters = "!@#$%^&*()-+";
string s;
ll n;

int main() {
cin>>n>>s; 
ll cnt=4;
ll c1=0,c2=0,c3=0,c4=0;
for(int i=0;i<n;i++)
{
	for(auto j:numbers)
	{
		if(s[i]==j)c1++;
	}
	for(auto j:lower_case)
	{
		if(s[i]==j)c2++;
	}
	for(auto j:upper_case)
	{
		if(s[i]==j)c3++;
	}
	for(auto j:special_characters)
	{
		if(s[i]==j)c4++;
	}
}
ll ans=0;
if(c1==0)ans++,n++;
if(c4==0)ans++,n++;
if(c3==0)ans++,n++;
if(c2==0)ans++,n++;
if(n<6)ans+=6-n;
cout<<ans<<endl;


	return 0;
           }