#include <iostream>
using namespace std;

class ld{
	public:
	int ldc(int w,int d);
};
int ld::ldc(int w,int d){
	if(d==1){
		return  int((w/d*d));
	}else{
		ldc(w-int((w/(d*d))),d-1);
		}
}

int main() {
	ld l;
	int w,d=0;
	cin >> w >> d;
	cout << l.ldc(w,d) << endl;
	return 0;
}