//A
/*==========================================================*/
/*    Template ver 2017-0720    |    Created by JollyBee    */
/* DOMINUS pascit me, et nihil mihi deerit (Psalmorum 23:1) */
/*==========================================================*/
#include<bits/stdc++.h>
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 double EPS=(double)1e-9;
const double PI=(double)acos(-1.0);
#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=l;i>=r;i-=c)
#define REV(i,l,r) REVV(i,l,r,1)
//random
int irand(int lo, int hi){
	return (((double)rand())/(RAND_MAX+1.0)) * (hi-lo+1) + lo;
}
//ll to string
string toString(ll x) {
	stringstream ss;
	ss << x;
	return ss.str();
}
//string to ll
ll toNumber(string S) {
	ll ret; 
	sscanf(S.c_str(),"%lld",&ret); 
	return ret;
}
// std::fill(start, end, value);
// for(auto it: DS){}

const int INF=(int)2e9;
const ll MOD=(ll)1e9+7;
/*==========================================================*/
/*                     END OF TEMPLATE                      */
/* DOMINUS pascit me, et nihil mihi deerit (Psalmorum 23:1) */
/*==========================================================*/

const string sdigit="0123456789";
const string sspeci="!@#$%^&*()-+";
const string slower="abcdefghijklmnopqrstuvwxyz";
const string supper="ABCDEFGHIJKLMNOPQRSTUVWXYZ";

int main(){
	int l;
	char s[105];
	scanf("%d %s",&l,s);
	bool upper=false, lower=false, speci=false, digit=false;
	FOR(i,l){
		for(auto c:sdigit) if(c==s[i])digit=true;
		for(auto c:sspeci) if(c==s[i])speci=true;
		for(auto c:slower) if(c==s[i])lower=true;
		for(auto c:supper) if(c==s[i])upper=true;
	}
	int ret=!upper+!lower+!speci+!digit;
	int res=max(max(6-l,ret),0);
	printf("%d\n",res);
	return 0;
}