#include <iostream>

using namespace std;

int main(int argc, const char* argv[])
{
	int W, D;
	cin >> W >> D;
	for (; D >= 1 && W > 0; D--) {
		if (D == 1) {
			cout << W << endl;
			return 0;
		}
		W = W - W / D / D;
	}
	cout << 0 << endl;
	return 0;
}