import java.util.*; import java.io.*; import java.math.*; public class No40 { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int d = Integer.parseInt(sc.nextLine()); String[] t = sc.nextLine().split(" "); // System.out.println("d = " + d); int[] a = new int[d+1]; for(int i = 0; i < d+1; i++) { a[i] = Integer.parseInt(t[i]); } // System.out.println(Arrays.toString(a)); int[] w = {0, -1, 0, 1}; for(int i = a.length-1; i > 2; i--) { int te = a[i] / w[3]; // for(int j = w.length-1; j >= 0; j--) { for(int c = 0; c < w.length; c++) { a[i-c] = a[i-c] - w[3-c]*te; } // System.out.println(Arrays.toString(a)); } // System.out.println(Arrays.toString(a)); int ji = 0; String str = ""; int cc = a.length >= 3? 2 : a.length-1; // for(int i = 2; -1 < i; i--) { for(int i = cc; -1 < i; i--) { if(a[i] != 0 && ji < i) { ji = i; } if(a[i] == 0) { if(!"".equals(str)) { str = a[i] + " " + str; } }else { str = a[i] + " " + str; } } System.out.println(ji); if("".equals(str)) { System.out.println(0); }else { System.out.println(str.trim()); } } }