#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string s) {
    // Return the minimum number of characters to make the password strong
    int lo=0,co=0,num=0,sp=0,l=0;
    if(s.length()>=6)
        l=1;
    
    for(int i=0;i<n;i++){
        if(s[i]>='0' && s[i]<='9')
            num=1;
        else if(s[i]>='a' && s[i]<='z')
            lo=1;
        else if(s[i]>='A' && s[i]<='Z')
                co=1;
        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=1;
        if(num==1 && lo==1 && co==1 && sp==1)
            break;
            
    }
    if(l==1 && num==1 && lo==1 && co==1 && sp==1)
        return 0;
    int k=0;
    if(num!=1)
        k++;
    if(lo!=1)
        k++;
    if(co==0)
        k++;
    if(sp!=1)
        k++;
    if(n+k<6){
        k+=6-(n+k);
    }
    return k;
}

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