What is the value return by the function: sum(struct TreeNode* root) where root is the head pointer of the binary tree passed?

int result = 0; void fun(struct TreeNode* root, bool flag) { if(!root->left && !root->right && flag) {  result += root->val;  return; } if(root->left) fun(root->left, true); if(root->right) fun(root->right, false);     } int sum(struct TreeNode* root){ if(root == NULL) return 0;  fun(root,false); return result; }

Definition for a binary tree node.
struct TreeNode {
int val;
struct TreeNode *left;
struct TreeNode *right;
};