#include <iostream>
using namespace std;
int main() {
long long a;
cin >> a;
int s = (a / 30) * 7;
a = a - (30 * s);
if (a == 0) {
cout << s;
}
else {
if (a > 24) {
s = s + 7;
}
else if (a > 20) {
s = s + 6;
}
else if (a > 18) {
s = s + 5;
}
else if (a > 15) {
s = s + 4;
}
else if (a > 12) {
s = s + 3;
}
else if (a > 10) {
s = s + 2;
}
else if (a > 6) {
s = s + 1;
}
cout << s;
}
}
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