using System;
public class Program
{
public static void Main()
var array = new int[] {0,1,0,3,12};
for (int i = 0; i < array.Length; i++)
int num = array[i];
if (num != 0)
continue;
for (int j = i + 1; j < array.Length; j++)
int num2 = array[j];
if (num2 == 0)
array[i] = num2;
array[j] = num;
break;
}
System.Console.WriteLine(array[i]);