#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) {
    // Return the minimum number of characters to make the password strong
    int words=0,i,criteria[4];
    for(i=0;i<4;i++)
        criteria[i]=0;
    for(i=0;i<n;i++)
    {
        if(password[i]>='0'&&password[i]<='9')
            criteria[0]=1;
        else if(password[i]>='a'&&password[i]<='z')
            criteria[1]=1;
        else if(password[i]>='A'&&password[i]<='Z')
            criteria[2]=1;
        else if(password[i]=='!'||password[i]=='@'||password[i]=='#'||password[i]=='$'||password[i]=='^'||password[i]=='&'||password[i]=='*'||password[i]=='('||password[i]==')'||password[i]=='-'||password[i]=='+')
            criteria[3]=1;
    }
    words=n;
    for(i=0;i<4;i++)
    {
        //printf("criteria:%d\n",criteria[i]);
        if(criteria[i]==0)
            words++;
    }
    if(words>=6)
        return words-n;
    return 6-n;
}

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;
}