#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int read()
{
	char ch=getchar();int f=0;
	while(ch<'0'||ch>'9')ch=getchar();
	while(ch>='0'&&ch<='9'){f=(f<<1)+(f<<3)+ch-'0';ch=getchar();}
	return f;
}
char s[100005];
bool vis[105];
int main()
{
	int n=read();
	scanf("%s",s+1);
	n=strlen(s+1);
	for(int i=1;i<=n;i++)
	{
		if(s[i]>='0'&&s[i]<='9') vis[1]=1;
		else if(s[i]>='a'&&s[i]<='z') vis[2]=1;
		else if(s[i]>='A'&&s[i]<='Z') vis[3]=1;
		else vis[4]=1;
	}
	int ans=0;
	for(int i=1;i<=4;i++)
	{
		if(!vis[i])
		ans++,n++;
	}
	ans+=max(6-n,0);
	cout<<ans;
}