#include<bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define pob pop_back
#define pf push_front
#define pof pop_front
#define FOR(i,n) for(int i=0;i<n;i++)
#define REPP(i,l,r,c) for(int i=l;i<=r;i+=c)
#define REP(i,l,r) REPP(i,l,r,1)
#define FORD(i,n) for(int i=n-1;i>=0;i--)
#define REVV(i,l,r,c) for(int i=r;i>=l;i-=c)
#define REV(i,l,r) REVV(i,l,r,1)
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef vector<pii> vii;

const int INF=(int)1e9;
const double EPS=(double)1e-9;
const double PI=(double)acos(-1.0);
const ll MOD=(ll)1e9+7;

int irand(int lo, int hi){
	return (((double)rand())/(RAND_MAX+1.0)) * (hi-lo+1) + lo;
}

string toString(ll x) {
	stringstream ss;
	ss << x;
	return ss.str();
}

ll toNumber(string S) {
	ll ret;
	sscanf(S.c_str(),"%lld",&ret);
	return ret;
}

void syncOff(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
}

string spe = "!@#$%^&*()-+";

int main(){
	int n;
	cin>>n;
	string s;
	cin>>s;
	int num=1, low=1, up=1, spes=1;
	FOR(i,n){
		if(s[i]>='0' && s[i]<='9') num=max(0,num-1);
		if(s[i]>='a' && s[i]<='z') low=max(0,low-1);
		if(s[i]>='A' && s[i]<='Z') up=max(0,up-1);
		FOR(j,spe.length()){
			if(s[i]==spe[j]){
				spes=max(spes-1,0);
				break;
			}
		}
	}
	int res=num+low+up+spes;
	cout<<max(res,6-n)<<endl;
	return 0;
}