在一棵非空二叉树中，若度为0的结点的个数n，度为2的结点个数为m，则有n=________ (系统根据字符串匹配来判定答案，所以您的答案中请不要包含空格) For a binary tree with at least one node, if there are n nodes with degree 0 and m nodes with degree 2, then n = ________（This problem is judged by string matching, Please make sure your answer don’t contain any blanks.）