BAC 4/2022 1 ***

#include <iostream>
using namespace std;

void duplicare(int n, int &d) {
    int p = 1, ok = 0;
    d = 0;
    while (n) {
        if (n % 2 == 0) {
            d = (n % 10) * p + d;
            p *= 10;
        } else {
            d = (n % 10) * p + d;
            p *= 10;
            d = (n % 10) * p + d;
            p *= 10;
            ok = 1;
        }
        n /= 10;
    }
    if (!ok) {
        d = -1;
    }
}

int main() {
    int d;
    duplicare(23450, d);//2334550
    cout << d << endl;
    return 0;
}