#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string a) {
    int ans=0;
    int x=0;
    if(a.length()<6)
    {
        x=abs(6-n);
    }
    int s=0;
    int flag1=0,flag2=0,flag3=0,flag4=0;
    for(int i=0;i<n;i++)
    {
        if(a[i]>='a' && a[i]<='z')
            flag1=1;
        if(a[i]>='A' && a[i]<='Z')
            flag2=1;
        if(a[i]>='0' && a[i]<='9')
            flag3=1;
        if(a[i]=='!' || a[i]=='@' || a[i]=='#' || a[i]=='$' || a[i]=='%' || a[i]=='^' || a[i]=='&' || a[i]=='*' || a[i]=='(' || a[i]==')' || a[i]=='-' || a[i]=='+')
            flag4=1;
    }
    if(flag1==0)
        s++;
    if(flag2==0)
        s++;
    if(flag3==0)
        s++;
    if(flag4==0)
        s++;
    ans=0;
    ans+=s;
    if(n+ans<6)
        ans+=6-n-ans;
    return ans;
    // Return the minimum number of characters to make the password strong
}

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