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

int getLength(char* password)
{
    int i = 0;
    while (*(password + i) != '\0')
    {
        i++;
    }
    
    return i;
}
bool hasDigit(char* password)
{
    bool result = false;
    int i = 0;
    
    while (*(password + i) != '\0')
    {
        if ((int)*(password + i) >= 48
           &&
           (int)*(password + i) <= 57)
        {
            result = true;
            break;
        }
        i++;
    }
    
    return result;
}

bool hasUpperCase(char* password)
{
    bool result = false;
    int i = 0;
    
    while (*(password + i) != '\0')
    {
        if ((int)*(password + i) >= 65
           &&
           (int)*(password + i) <= 90)
        {
            result = true;
            break;
        }
        i++;
    }
    
    
    
    return result;
}

bool hasLowerCase(char* password)
{
    bool result = false;
    
    int i = 0;
    
    while (*(password + i) != '\0')
    {
        if ((int)*(password + i) >= 97
           &&
           (int)*(password + i) <= 122)
        {
            result = true;
            break;
        }
        i++;
    }
    
    return result;
}

bool hasSpecialCharacter(char* password)
{
    bool result = false;
    
    int i = 0;
    
    while (*(password + i) != '\0')
    {
        if ((int)*(password + i) == 33
           ||
           (int)*(password + i) <= 38 && (int)*(password + i) >= 35
           ||
           (int)*(password + i) <= 45 && (int)*(password + i) >= 40
            ||
           (int)*(password + i) == 64
            ||
           (int)*(password + i) == 94)
        {
            result = true;
            break;
        }
        i++;
    }
    
    return result;
}

int minimumNumber(int n, char* password) {
    // Return the minimum number of characters to make the password strong
    int needChar = 0;
    
    if (!hasDigit(password))
        needChar++;
    if (!hasUpperCase(password))
        needChar++;
    if (!hasLowerCase(password))
        needChar++;
    if (!hasSpecialCharacter(password))
        needChar++;
    
    int result = 0;
    
    int lenCurrentPW = getLength(password);
    
    if (lenCurrentPW >= 6)
    {
        result = needChar;
    }
    else
    {
        int delta = 6 - lenCurrentPW;
        if (delta >= needChar)
            result = delta;
        else
            result = needChar;
    }
    
    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;
}