#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int a[5];
    int count=0,count1=0;
    for(int i=0;i<5;i++)
       a[i]=0;
    int n;
    cin>>n;
    if(n>=6)    a[0]=1;
    else count1=(6-n);
    string s;
    cin>>s;
    for(int i=0;i<n;i++)
    {
        if(s[i]>=48 && s[i]<=57)
            a[1]=1;
        if(s[i]>=65 && s[i]<=90)
            a[2]=1;
        if(s[i]>=97 && s[i]<=122)
            a[3]=1;
        if(((((((((((s[i]=='!' || s[i]=='@')||s[i]=='#')||s[i]=='$')||s[i]=='^')||s[i]=='%')||s[i]=='&')||s[i]=='*')||s[i]=='(')||s[i]==')')||s[i]=='-')||s[i]=='+')
            a[4]=1;
    }
    for(int i=0;i<5;i++)
    {  // cout<<a[i]<<" ";
        if(a[i]==0 && i!=0)
            count++;
    }//cout<<endl;
    cout<<max(count,count1)<<endl;
    return 0;
}