#include
using namespace std;
class node{
public:
int data;
nodeleft;
noderight;
node(int d){
int data=d;
node*left=NULL;
node*right=NULL;
}
};
node* insertinBST(node*root,int data){
//base case
if(root==NULL){
return new node(data);
}
//rec case
if(data<=root->data){
root->left=insertinBST(root->left,data);
}
else{
root->right=insertinBST(root->right,data);
}
return root;
}
node* buildBST(){
int data;
cin>>data;
node*root=NULL;
while(data!=-1){
root=insertinBST(root,data);
cin>>data;
}
return root;
}
void printpreorder(node*root){
if(root==NULL){
return;
}
cout<<root->data<<" ";
printpreorder(root->left);
printpreorder(root->right);
}
int main() {
node*root=buildBST();
printpreorder(root);
cout<<endl;
// printlevelorder(root);
}
