#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 a[]) {
    int c=0;
    int uc=0;
    int lc=0;
    int sc=0;
    for(int i=0;i<n;i++){
        if(a[i]>='A'&&a[i]<='Z')
            uc++;
        if(a[i]>='a'&&a[i]<='z')
            lc++;
        if(a[i]=='!'||a[i]=='@'||a[i]=='#'||a[i]=='$'||a[i]=='%'||a[i]=='^'||a[i]=='&'||a[i]=='*'||a[i]=='('||a[i]==')'||a[i]=='-'||a[i]=='+')
            sc++;
        if(a[i]>='0'&&a[i]<='9')
            c++;
    }
    int tc=4;
    if(lc!=0)
        tc--;
    if(uc!=0)
        tc--;
    if(sc!=0)
        tc--;
    if(c!=0)
        tc--;
    if(strlen(a)<6){
        if(6-strlen(a)<tc)
            return(tc);
        return(6-strlen(a));
    }
    return(tc);
    
    // 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;
}