```
class Solution {
public:
TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {
if(p->val<root->val && q->val<root->val)
return lowestCommonAncestor(root->left,p,q);
if(p->val>root->val && q->val>root->val)
return lowestCommonAncestor(root->right ,p,q);
return root;
}
};
```