public class Main4 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int year = sc.nextInt();
        int increase = 2;
        int cowCount = 0;
        // key为age，value为数量
        Map<Integer, Integer> map = new TreeMap<Integer, Integer>();
        // 1岁的牛只有一头，初始化值
        map.put(1, 1);
        while(increase <= year){
            // 更新map中的key，表示年龄
            Map<Integer, Integer> newCows = new TreeMap<Integer, Integer>();
            // 表示存储具有生育能力的牛的数量
            int canBorn = 0;
            for(Entry<Integer, Integer> entry:map.entrySet()){
                if(entry.getKey() + 1 <= 10){
                    newCows.put(entry.getKey() + 1, entry.getValue());
                    if(entry.getKey() >= 2 && entry.getKey() <= 6){
                        // 年龄在3-7岁，生一只牛
                        canBorn += entry.getValue();
                    }
                }
            }
            if(canBorn != 0){
                newCows.put(1, canBorn);
            }
            map = newCows;
            increase++;
        }
        
        for(Entry<Integer, Integer> entry:map.entrySet()){
            cowCount += entry.getValue();
        }
        System.out.println(cowCount);
    }
}