//入力文字読み取り
    process.stdin.resume();
    process.stdin.setEncoding('utf8');
    process.stdin.on('data', function (chunk) {

        //数値に変換
        var viscuit = Number(chunk);
        var sum = 1
        var count = 0
        while (true) {
            if (viscuit <= sum) {
                break;
            }
            sum *= 2
            count++
        }
        console.log(count)
    });