#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 result=0,x,cA=0,ca=0,cs=0,cd=0,i;
    char*st=password;
        for(i=0;i<n;i++)
        {
            if(st[i]>=65&&st[i]<=90)
                cA=1;
            else if(st[i]>=97&&st[i]<=122)
                ca=1;
            else if(st[i]>=48&&st[i]<=57)
                cd=1;
            else if(st[i]=='!'||st[i]=='@'||st[i]=='#'||st[i]=='$'||st[i]=='%'||st[i]=='^'||st[i]=='&'||st[i]=='*'||st[i]=='('||st[i]==')'||st[i]=='-'||st[i]=='+')
                cs=1;
        }
        if(cA==0)
            result++;
        if(ca==0)
            result++;
        if(cd==0)
            result++;
        if(cs==0)
            result++;
    if(result+n<6)
    {
        x=6-(result+n);
        result=result+x;
    }
    return result;
}

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;
}