Model2020MIs3e1.cpp

#include <iostream>
using namespace std;

void duplicare(int n, int &d) {
	
	int p = 1, are_cifre_impare = 0;
	d = 0;

	while (n > 0) {
		int ultima_cifra = n % 10;
		if (n % 2 == 1) {
			are_cifre_impare = 1;
			d = p * ultima_cifra + d;
			p = p * 10;
		}
		
		d = p * ultima_cifra + d;
		p = p * 10;
		n = n / 10;
	}

	// daca nu are cifre impare
	if (are_cifre_impare == 0) {
		d = -1;
	}

	
}

int main() {
	int n, d;
	cin >> n;
	duplicare(n, d);

	cout << d << endl;

	return 0;

}