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

void minimumNumber(int n, char* p) {
    // Return the minimum number of characters to make the password strong
    int i,a,b,c,d;
    a=1;b=1;c=1;d=1;
    for(i=0;p[i]!='\0';i++)
    {
        if(p[i]>=48&&p[i]<=57)
            a=0;
        else
            if(p[i]>=97&&p[i]<=122)
                b=0;
        else
            if(p[i]>=65&&p[i]<=90)
                c=0;
        else if(p[i]==33||(p[i]>=35&&p[i]<=38)||(p[i]>=40&&p[i]<=43)||p[i]==64||p[i]==94||p[i]==45)
            d=0;
    }
    if(n>=6)
        printf("%d",a+b+c+d);
    else
    {
        if((6-n)>(a+b+c+d))
            printf("%d",6-n);
        else
            printf("%d",a+b+c+d);
    }
}

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