#include <iostream>

using namespace std;

int main()

{

int mas[20] = {};

for (int jjj = 0; jjj < 20; jjj++)

{

cin >> mas[jjj];

if (cin.fail())

{

cin.clear();

cin.ignore(32000, '\n');

break;

};

};

cout<<"\nДо : ";

for(int jjj:mas)cout<<jjj<<" ";

for (int kkk{0} ,jjj{0}; jjj <20; jjj++)

if (mas[jjj] == 0)

swap(mas[kkk++], mas[jjj]);

cout<<"\nПосле : ";

for(int jjj:mas)cout<<jjj<<" ";

}