#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    int n, pred = 0, flag1 = 0, flag2 = 0, flag3 = 0, flag4 = 0, flag5 = 0;
    string s;
    cin>>n;
    cin>>s;
    if(n < 6){
        flag1 = 1;
    }
    for(int i = 0; i<n; i++){
        if(s[i] >= 65 and s[i] <= 90){
            flag2 = 1;
            break;
        }
    }
    for(int i = 0; i<n; i++){
        if(s[i] >= 97 and s[i] <= 122){
            flag3 = 1;
            break;
        }
    }
    for(int i = 0; i<n; i++){
        if(s[i] >= 48 and s[i] <= 57){
            flag4 = 1;
            break;
        }
    }
    // !@#$%^&*()-+
    for(int i = 0; i<n; i++){
        if(s[i] == '!' || s[i] =='@' || s[i] == '#' || s[i] == '$' || s[i] == '%' || s[i] == '^' || s[i] == '&' || s[i] == '*' || s[i] == '(' || s[i] == ')' || s[i] == '-' || s[i] == '+'){
            flag5 = 1;
            break;
        }
    }
    if(flag2 == 0){
        pred += 1;
    }
    if(flag3 == 0){
        pred += 1;
    }
    if(flag4 == 0){
        pred += 1;
    }
    if(flag5 == 0){
        pred += 1;
    }
    if(flag1 == 1){
        cout<<max(6-n, pred);
    }else{
        cout<<pred;
    }
    return 0;
}