#include<bits/stdc++.h>
using namespace std;
const int N = 2.5e5 + 5;
#define MOD 1000000007
#define lli long long int
#define ulli unsigned long long int
#define fr first
#define sc second
#define INF 1e9
#define p_b push_back
#define m_p make_pair
/*int id[100006];
int find_root(int i){
	while(id[i]!=i){
		id[i]=id[id[i]];
		i=id[i];
	}
	return i;
}
void union1(int a,int b){
	int root_a=find_root(a);
	int root_b=find_root(b);
	id[root_a]=id[root_b];
}*/
/*lli BITS[1050]={0};
void update_bits(int i,int val){
	while(i<1050){
		//cout<<i<<" ";
		BITS[i]+=val;
		i+=( i & (-i));
	}
}
lli getsum(int ind){
	lli ret=0;
	while(ind>0){
		ret+=BITS[ind];
		ind-=(ind & (-ind));
	}
	return ret;
}*/
int main(){
	
	int n;
	cin>>n;
	int dig=0,uc=0,lc=0,sc=0;
	string st;
	cin>>st;
	for(int i=0;i<n;i++){
		if(st[i]-'0'>=0 && st[i]-'0'<=9){ dig++; continue; }
		if(st[i]-'a'>=0 && st[i]-'a'<26){ lc++; continue; }
		if(st[i]-'A'>=0 && st[i]-'A'<26){ uc++; continue; }
		sc++;
	}	
	int ans=0;
	if(dig==0){ ans++; }
	if(uc==0){ ans++; }
	if(lc==0){ ans++; }
	if(sc==0){ ans++; }
	n+=ans;
	if(n<6){ ans+=(6-n); }
	cout<<ans;
}