//Bismillah hirrahmanir rahim.//
#include<bits/stdc++.h>
using namespace std;
string low,up,spe,num;


int main()
{
    int n;
    num = "0123456789";
    low = "abcdefghijklmnopqrstuvwxyz";
    up = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    spe = "!@#$%^&*()-+";
    string ss;
    cin >> n;
    cin >> ss;
    int nn,mm,dd,ee;
    nn = mm = dd = ee = 0;
    for(int i=0; i<n; i++){
        if(num.find(ss[i])!=-1)nn++;
        if(low.find(ss[i])!=-1)mm++;
        if(up.find(ss[i])!=-1)dd++;
        if(spe.find(ss[i])!=-1)ee++;
    }
    int one = 0;
    if(!nn)one++;
    if(!mm)one++;
    if(!dd)one++;
    if(!ee)one++;
    int ans = one;
    ans = max(ans,(6-n));
    cout << ans << endl;
}