#include <bits/stdc++.h>
using namespace std;

string numbers[4] = {"0123456789","abcdefghijklmnopqrstuvwxyz","ABCDEFGHIJKLMNOPQRSTUVWXYZ","!@#$%^&*()-+"};
int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */ 
    int n;string p;cin>>n>>p;
    set<char> s[4];
    int need=4;
    for(int i=0;i<4;i++){
        for(char c:numbers[i]){
            s[i].insert(c);
        }
        for(char cc:p){
            if(s[i].count(cc)){
                need--;
                break;
            }
        }
    }
    cout<<max(need,6-n)<<endl;
    return 0;
}