import java.io.IOException; import java.io.InputStream; import java.util.NoSuchElementException; public class Main { public static void main(String args[]) { FastScanner scanner = new FastScanner(); int d=scanner.nextInt(); int[] a=new int[d+1]; for(int i=0;i<=d;i++) { a[i]=scanner.nextInt(); } int s = d; while (s != 2) { for (int i = 9; i >= 0; i--) { if (a[s] < 1 * i) continue; else if (a[s] == 1 * i && a[s - 1] < 0) continue; else if (a[s] == 1 * i && a[s - 1] == 0 && a[s - 2] < -1 * i) continue; else if (a[s] == 1 * i && a[s - 1] == 0 && a[s - 2] == -1 * i && a[s - 3] < 0) continue; a[s] = a[s] - 1 * i; a[s - 1] = a[s - 1] - 0; a[s - 2] = a[s - 2] - (-1 * i); a[s - 3] = a[s - 3] - 0; break; } s--; } int st=0; for(int i=0;i<=d;i++) { if(a[i]!=0) { st=i; break; } } int en=0; for(int i=d;i>=0;i--) { if(a[i]!=0) { en=i; break; } } System.out.println(en); for(int i=st;i<=en;i++) { System.out.print(a[i]+" "); } System.out.println(); } } class FastScanner { private final InputStream in = System.in; private final byte[] buffer = new byte[1024]; private int ptr = 0; private int buflen = 0; private boolean hasNextByte() { if (ptr < buflen) { return true; }else{ ptr = 0; try { buflen = in.read(buffer); } catch (IOException e) { e.printStackTrace(); } if (buflen <= 0) { return false; } } return true; } private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;} private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;} public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();} public String next() { if (!hasNext()) throw new NoSuchElementException(); StringBuilder sb = new StringBuilder(); int b = readByte(); while(isPrintableChar(b)) { sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } public long nextLong() { if (!hasNext()) throw new NoSuchElementException(); long n = 0; boolean minus = false; int b = readByte(); if (b == '-') { minus = true; b = readByte(); } if (b < '0' || '9' < b) { throw new NumberFormatException(); } while(true){ if ('0' <= b && b <= '9') { n *= 10; n += b - '0'; }else if(b == -1 || !isPrintableChar(b)){ return minus ? -n : n; }else{ throw new NumberFormatException(); } b = readByte(); } } public int nextInt() { long nl = nextLong(); if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException(); return (int) nl; } public double nextDouble() { return Double.parseDouble(next());} }