#include <bits/stdc++.h>

using namespace std;



int main() {
    long long int n,i,j,k=0,c=0,num=0,sp=0,d=0,l=0;
    string s;
    cin>>n;
    cin>>s;
    for(i=0;i<n;i++)
    {
        if(s[i]>=65&&s[i]<=90)
            c++;
        else if(s[i]>=97&&s[i]<=122)
            k++;
        else if(s[i]>='0'&&s[i]<='9')
            num++;
       
       else 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]=='+')
           sp++;
    }
    if(sp>=1&&num>=1&&c>=1&&k>=1&&n>=6)
        cout<<"0";
    else if(sp>=1&&num>=1&&c>=1&&k>=1&&n<6)
        cout<<(6-n);
    else
    {
        if(sp>=1)
         d++;
        if(num>=1)
         d++;
        if(k>=1)
         d++;
        if(c>=1)
         d++;
        if(d<4)
        {
        n=n+(4-d);
            l=l+(4-d);
         if(n<6)
             cout<<(l+6-n);
            else
                cout<<l;
            }
}
    return 0;
}