#include <iostream>
#include <math.h>

using namespace std;

void nhap(int &n) {
	do {
		cout<<"Nhap so nguyen duong: "; cin>>n;
		if (n < 0) cout<<"Vui long nhap lai"<<endl; 
	} while (n < 0);
}

int nhi_phan1(int n) {
	int bin = 0;
	int vitri = 1;
	while (n != 0) {
		bin += n % 2 * vitri;
		n /= 2;
		vitri *= 10;
	}
	return bin;
}

int nhi_phan2(int n) {
    if (n == 0) return 0;
    return nhi_phan2(n/2) * 10 + n % 2;
}

int main() {
	int n;
	nhap(n);
	cout<<"Ket qua la: "<<nhi_phan2(n);
	return 0;
}