process.stdin.resume();
process.stdin.setEncoding('ascii');

var input_stdin = "";
var input_stdin_array = "";
var input_currentline = 0;

process.stdin.on('data', function (data) {
    input_stdin += data;
});

process.stdin.on('end', function () {
    input_stdin_array = input_stdin.split("\n");
    main();    
});

function readLine() {
    return input_stdin_array[input_currentline++];
}

/////////////// ignore above this line ////////////////////

function minimumNumber(n, password) {
    const numbers = "0123456789"
    const lower_case = "abcdefghijklmnopqrstuvwxyz"
    const upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    const special_characters = "!@#$%^&*()-+"
    password = password.split``
    let count = 0
    if(!password.filter(e=>numbers.includes(e)).length) {
        count++
    } 
    if(!password.filter(e=>lower_case.includes(e)).length) {
        count++
    } 
    if(!password.filter(e=>upper_case.includes(e)).length) {
        count++
    } 
    if(!password.filter(e=>special_characters.includes(e)).length) {
        count++
    } 
     
    
    
    // Return the minimum number of characters to make the password strong
    
    return n+count >= 6 ? count : count + (6 - n - count)
}

function main() {
    var n = parseInt(readLine());
    var password = readLine();
    var answer = minimumNumber(n, password);
    process.stdout.write("" + answer + "\n");

}