input

$myposts = get_posts($args);

				foreach( $myposts as $post ) : setup_postdata($post);

                     $checked = is_array($cats) && in_array(get_the_ID(), $cats) ? 'checked="checked"' : '';

				 ?>

					<label><input <?php echo  $checked; ?> type="checkbox" name="myposts[]" value="<?php the_ID(); ?>" id="myposts[]" /><?php the_title(); ?></label>
					<br>
					Custo <input type="text" name="etapa_custo[<?php echo $post_id?>]" value="" />

					<br>

				 <?php

				 endforeach;

            }


}

			add_action( 'save_post', 'salvar_post_etapas' );
			function salvar_post_etapas( $post_id ){
				if( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) return;
				if( isset( $_POST['myposts'])){
						update_post_meta( $post_id, 'myposts', $_POST['myposts']);

				}else{
						  update_post_meta( $post_id, 'myposts', array());
				}


			}