#include<iostream>
#include<vector>
#include<algorithm>
#include<string.h>
#include<cstdio>
#include<math.h>
#include<cstdlib>
#include<map>
#include<unordered_map>
#include<utility>
#include<stack>
#include<fstream>
#include<set>
#include<queue>
#include<iomanip>

using namespace std;

#define ll long long int
#define ld long double

const ll inf = 1e+15;
const ll mod = 1e9+7;

#define cincout ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define me(a,i) memset(a,i,sizeof(a))
#define mp make_pair
#define VLL vector <ll>
#define PLL pair <ll,ll>
#define VLD vector <ld>
#define pb push_back
#define sortv(v) sort(v.begin(),v.end())
#define sortvd(v) sort(v.begin(),v.end(),greater<int>())
#define printv(n,v) for(int i=0;i<n;i++)  {cout<<v[i]<<" ";}
#define vin(v,n,a) for(int i=0;i<n;i++)	{v.pb(a);cin>>v[i];}
#define FIT(it,v) for (typeof(v.begin()) it = v.begin(); it != v.end(); it++)
#define FF(i,a,b) for (int i = (a); i < (b); i++)
#define FD(i,a,b) for (int i = (a); i >= (b); i--)

string s;
int n,ans=0,lo=0,up=0,di=0,sp=0;

int main(){
	cincout;
	cin>>n>>s;
	FF(i,0,s.length()){
		if(s[i]>='a' && s[i]<='z')
			lo=1;
		else if(s[i]>='A' && s[i]<='Z')
			up=1;
		else if(s[i]>='0' && s[i]<='9')
			di=1;
		else if(s[i]=='!' || s[i]=='@'||s[i]=='#'||s[i]=='$'||s[i]=='%'||s[i]=='^'||s[i]=='&'||s[i]=='*'||s[i]=='('||s[i]==')'||s[i]=='-'||s[i]=='+')
			sp=1;
	}
	if(lo==0){
		ans++;
		s+="a";
	}
	if(up==0){
		ans++;
		s+="b";
	}
	if(di==0){
		ans++;
		s+="c";
	}
	if(sp==0){
		ans++;
		s+="d";
	}
	if(s.length()<6)
		ans+= (6-s.length());
	cout<<ans<<endl;
  	return 0;
}