class Solution {
public:
    TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* n1, TreeNode* n2) {
       if(root == NULL) return NULL;
       if((root->val == n1->val)|| (root->val == n2->val)){
           return root;
       }
       TreeNode* leftans = lowestCommonAncestor(root->left,n1,n2);
       TreeNode* rightans = lowestCommonAncestor(root->right,n1,n2);
       if(leftans != NULL && rightans != NULL ) return root;
       else if(leftans != NULL && rightans ==NULL) return leftans;
       else if(leftans == NULL && rightans !=NULL) return rightans;
       else return NULL;
    }
};