#include <iostream>
using namespace std;

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

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