#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string p) {
    
   int x=p.length(),no=0,l=0,u=0,sum,s=0;
    for(int i=0;i<x;i++)
    {
         if(p[i]>=48&&p[i]<=57)
              no++;
        
         if(p[i]>=65&&p[i]<=90)
              l++;
        
         if(p[i]>=97&&p[i]<=122)
              u++;
        else if(p[i]=='!'||p[i]=='@'||p[i]=='#'||p[i]=='$'||p[i]=='%'||p[i]=='^'||p[i]=='&'||p[i]=='*'||p[i]=='('||p[i]==')'||p[i]=='-'||p[i]=='+' )
            s++;
    }
    if(x>=6)
    {
        if(no==0)
            sum++;
        if(l==0)
             sum++;
        if(u==0)
             sum++;
        if(s==0)
             sum++;
    }
    else
    {
        if(no==0)
            sum++;
        if(l==0)
             sum++;
        if(u==0)
             sum++;
        if(s==0)
             sum++;
        
        int y=6-(sum+x);
        
        if(y>0)
             sum+=y;
           
    }
    
    return sum;
}

int main() {
    int n;
    cin >> n;
    string password;
    cin >> password;
    int answer = minimumNumber(n, password);
    cout << answer << endl;
    return 0;
}