#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

int minimumNumber(int n, char* password) {
    int i,c=4,r,t;
    for(i=0;i<n;i++){
        if(password[i]>=65&&password[i]<=90){
            c--;
            break;
        }}
   // printf("%d\n",c);
        for(i=0;i<n;i++){
        if(password[i]>=97&&password[i]<=122){
            c--;
            break;
        }}
     //printf("%d\n",c);
            for(i=0;i<n;i++){
        if(password[i]>=48&&password[i]<=57){
            c--;
            break;
        }}
     //printf("%d\n",c);
                for(i=0;i<n;i++){
        if(password[i]=='!'||password[i]=='@'||password[i]=='#'||password[i]=='$'||password[i]=='%'||password[i]=='^'||password[i]=='&'||password[i]=='*'||password[i]=='('||password[i]==')'||password[i]=='-'||password[i]=='+'){
            c--;
            break;
        }}
    // printf("%d\n",c);
            if(n>=6)
                r=c;
                    else{
                        t=(6-n);
                    if(t>c)
                    r=t;
                    else
                    r=c;}
            return r;
    // Return the minimum number of characters to make the password strong
}

int main() {
    int n; 
    scanf("%i", &n);
    char* password = (char *)malloc(512000 * sizeof(char));
    scanf("%s", password);
    int answer = minimumNumber(n, password);
    printf("%d\n", answer);
    return 0;
}