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