#include <bits/stdc++.h>
using namespace std;
char ch;
int n,digit,upper,lower,flag,Else;
int main(){
    cin>>n;
    for (int i=1; i<=n; i++){
        cin>>ch;
        if (ch>='0'&&ch<='9') ++digit;
        else if (ch>='a'&&ch<='z') ++lower;
        else if (ch>='A'&&ch<='Z') ++upper;
        else ++Else;
    }
    flag+=min(digit,1);
    flag+=min(lower,1);
    flag+=min(upper,1);
    flag+=min(Else,1);
    cout<<max(6-n,4-flag);
}