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) {
    // Return the minimum number of characters to make the password strong
    cap = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
    small = 'abcdefghijklmnopqrstuvwxyz';
    num = '0123456789';
    spec = '!@#$%^&*()-+'
    cap_ = 0;
    small_ = 0;
    num_ = 0;
    spec_ = 0;
    for(i=0;i<password.length;i++){
        for(j=0;j<cap.length;j++)if(cap[j] == password[i])cap_++;
        for(j=0;j<small.length;j++)if(small[j] == password[i])small_++;
        for(j=0;j<num.length;j++)if(num[j] == password[i])num_++;
        for(j=0;j<spec.length;j++)if(spec[j] == password[i])spec_++;
    }
    count = 0;
    if(cap_ == 0)count++;
    if(small_ == 0)count++;
    if(num_ == 0)count++;
    if(spec_ == 0)count++;
    temp = count+password.length;
    if(temp < 6)count += 6 - temp;
    return count;
}

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

}