package adv2016; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import java.io.PrintWriter; import java.util.Arrays; import java.util.InputMismatchException; public class N451 { InputStream is; PrintWriter out; String INPUT = ""; void solve() { int n = ni(); long[] b = new long[n]; for(int i = 0;i < n;i++){ b[i] = nl(); } // b[0]=a[0]+a[1], b[1]=a[1]-a[2] long[] a = new long[n+1]; for(int i = 1;i < n+1;i++){ if((i&1) == 1){ a[i] = b[i-1] - a[i-1]; }else{ a[i] = a[i-1] - b[i-1]; } if(Math.abs(a[i]) > 3e18){ out.println(-1); return; } } long min = 0; for(int i = 0;i < n+1;i++){ if((i&3) == 0 || (i&3) == 3){ min = Math.min(min, a[i]); } } for(int i = 0;i < n+1;i++){ if((i&3) == 0 || (i&3) == 3){ a[i] -= min-1; }else{ a[i] += min-1; } } long max = Long.MIN_VALUE; for(int i = 0;i < n+1;i++){ if((i&3) == 1 || (i&3) == 2){ max = Math.max(max, a[i]); } } if(max > 1000000000000000000L){ for(int i = 0;i < n+1;i++){ if((i&3) == 1 || (i&3) == 2){ a[i] -= max-1000000000000000000L; }else{ a[i] += max-1000000000000000000L; } } } for(int i = 0;i < n+1;i++){ if(1 <= a[i] && a[i] <= 1000000000000000000L){ }else{ out.println(-1); return; } } out.println(n+1); for(int i = 0;i < n+1;i++){ out.println(a[i]); } } void run() throws Exception { is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes()); out = new PrintWriter(System.out); long s = System.currentTimeMillis(); solve(); out.flush(); if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms"); // Thread t = new Thread(null, null, "~", Runtime.getRuntime().maxMemory()){ // @Override // public void run() { // long s = System.currentTimeMillis(); // solve(); // out.flush(); // if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms"); // } // }; // t.start(); // t.join(); } public static void main(String[] args) throws Exception { new N451().run(); } private byte[] inbuf = new byte[1024]; public int lenbuf = 0, ptrbuf = 0; private int readByte() { if(lenbuf == -1)throw new InputMismatchException(); if(ptrbuf >= lenbuf){ ptrbuf = 0; try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); } if(lenbuf <= 0)return -1; } return inbuf[ptrbuf++]; } private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); } private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; } private double nd() { return Double.parseDouble(ns()); } private char nc() { return (char)skip(); } private String ns() { int b = skip(); StringBuilder sb = new StringBuilder(); while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ') sb.appendCodePoint(b); b = readByte(); } return sb.toString(); } private char[] ns(int n) { char[] buf = new char[n]; int b = skip(), p = 0; while(p < n && !(isSpaceChar(b))){ buf[p++] = (char)b; b = readByte(); } return n == p ? buf : Arrays.copyOf(buf, p); } private int[] na(int n) { int[] a = new int[n]; for(int i = 0;i < n;i++)a[i] = ni(); return a; } private long[] nal(int n) { long[] a = new long[n]; for(int i = 0;i < n;i++)a[i] = nl(); return a; } private char[][] nm(int n, int m) { char[][] map = new char[n][]; for(int i = 0;i < n;i++)map[i] = ns(m); return map; } private int[][] nmi(int n, int m) { int[][] map = new int[n][]; for(int i = 0;i < n;i++)map[i] = na(m); return map; } private int ni() { return (int)nl(); } private long nl() { long num = 0; int b; boolean minus = false; while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')); if(b == '-'){ minus = true; b = readByte(); } while(true){ if(b >= '0' && b <= '9'){ num = num * 10 + (b - '0'); }else{ return minus ? -num : num; } b = readByte(); } } private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); } }