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 reNum = /[0-9]/;
    const reLower = /[a-z]/;
    const reUpper = /[A-Z]/;
    const specialChars = new Set(['!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '-', '+']);
    
    let numNeeded = 0;
    
    if (!reNum.test(password)) {
        ++numNeeded;
    }
    if (!reLower.test(password)) {
        ++numNeeded;
    }
    if (!reUpper.test(password)) {
        ++numNeeded;
    }
    if (!password.split('').some(letter => specialChars.has(letter))) {
        ++numNeeded;
    }
    
    if (n < 6) {
        numNeeded = Math.max(numNeeded, 6-n);
    }
    
    return numNeeded;
}

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

}