#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
#define pb push_back
#define len(a) (int)a.size()
#define all(a) (a.begin(),a.end())
#define fi first
#define sc second
#define ort(x,y) (x+y)/2
#define endl '\n'
#define FAST ios_base::sync_with_stdio(false);
#define d1(x) cerr<<#x<<":"<<x<<endl;
#define d2(x,y) cerr<<#x<<":"<<x<<" "<<#y<<":"<<y<<endl;
#define d3(x,y,z) cerr<<#x<<":"<<x<<" "<<#y<<":"<<y<<" "<<#z<<":"<<z<<endl;
#define lim (int) (105)
#define inf (int) (1e7)
#define heap priority_queue
#define mem(a,val) memset(a,val,sizeof(a))
#define y1 asdassa
typedef long long int lli;
typedef pair<int,int> pii;
typedef pair<pair<int,int>,int> piii;
char s[lim];
int mark[lim],l;
int main()
{
	scanf("%d %s",&l,s+1);
	for(int i=1;i<=l;i++)
	{
		char c=s[i];
		if(c>='a' && c<='z') mark[1]=1;
		if(c>='A' && c<='Z') mark[2]=1;
		if(c>='0' && c<='9') mark[3]=1;
		if(c=='!' || c=='@' || c=='#' || c=='%' || c=='^' || c=='&' || c=='*' || c=='(' || c==')' || c=='-' || c=='+' || c=='$') mark[4]=1;
	}
	int ans=0;
	if(!mark[1]) ans++,l++;
	if(!mark[2]) ans++,l++;
	if(!mark[3]) ans++,l++;
	if(!mark[4]) ans++,l++;
	if(l<6) return printf("%d\n",6-l+ans),0;
	printf("%d\n",ans);
}