#include <iostream>
using namespace std;

int main() {
    int age;
    cin >> age;

    int daily_dose;
    if (age > 10) {
        daily_dose = 25 * 3;
    } else if (age >= 7) {
        daily_dose = 15 * 3;
    } else {
        daily_dose = 5 * 3;
    }

    int total_dose = daily_dose * 5;
    int bottle_capacity = 120;
    int num_bottles = (total_dose + bottle_capacity - 1) / bottle_capacity;

    cout << num_bottles << endl;
    return 0;
}    
/**************************************************************
	Problem: 1310
	User: linmiaoling
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2072 kb
****************************************************************/