import std.algorithm, std.array, std.container, std.range;
import std.string, std.conv, std.math;
import std.stdio, std.typecons;

void main()
{
  auto d = readln.chomp.to!int;
  auto ai = readln.split.map!(to!int).array;

  ai.reverse();
  while (ai.length > 3) {
    auto a = ai.front;
    ai[0] -= a;
    ai[2] += a;
    ai = ai.find!("a != 0");
  }

  if (ai.empty) {
    writeln(0);
    writeln(0);
  } else {
    ai.reverse();
    writeln(ai.length - 1);
    writeln(ai.map!(to!string).join(" "));
  }
}