#include <bits/stdc++.h>

using namespace std;


int minimumNumber(int n, string s) {
    int a,A,d,c,flag,p,q,i;
    a=0;A=0;flag=1;c=0;d=0;
    for(i=0;i<n;i++)
    {
        if(s[i]>=97&&s[i]<=122)
            a++;
        if(s[i]>=65&&s[i]<=90)
            A++;
        if(isdigit(s[i]))
            d++;
        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]=='+')
            c++;
        if(a>0&&A>0&&d>0&&c>0)
        {
            flag=0;
            break;
        }
    }
    if(flag==0)
        p=6-n;
    else if((a>0&&A>0&&d>0&&c==0)||(a>0&&A>0&&d==0&&c>0)||(a>0&&A==0&&d>0&&c>0)||(a==0&&A>0&&d>0&&c>0))
    {
        q=5-n;
        if(q>=0)
            p=q+1;
        else
            p=1;
    }
    else if((a==0&&A>0&&d>0&&c==0)||(a>0&&A>0&&d==0&&c==0)||(a>0&&A==0&&d==0&&c>0)||(a==0&&A==0&&d>0&&c>0)||(a==0&&A>0&&d==0&&c>0)||(a>0&&A==0&&d>0&&c==0))
    {
        q=4-n;
        if(q>=0)
            p=q+2;
        else
            p=2;
    }
    else if(a==0&&A==0&&c==0&&d==0)
    {q=2-n;
    if(q>=0)
        p=q+4;
    else
        p=4;}
    else
    {
        q=3-n;
        if(q>=0)
            p=q+3;
        else
            p=3;
    }
    if(flag==0)
    {
        if(p<0)
            p=0;
    }
    return p;
}

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