#include <iostream>

typedef struct REF2{
    int value;
    REF2 * left = NULL;
    REF2 * right = NULL;
}ref2;

void dodaj(ref2 *t, int value){
    if (t==NULL){
        ref2* nowy = new ref2 {value};
        t = nowy;
    }else if(value<t->value){
        dodaj(t->left, value);
    }else {
        dodaj(t->right, value);
    }
}
std::ostream& operator << (std::ostream& stream, ref2* bst){
    if (bst->left!=NULL) {
        stream<<bst->left;
    }
    stream<<bst->value<<" ";
    if (bst->right!=NULL) {
        stream<<bst->right;
    }
    return stream;
}

int main(){
    ref2* tree = new ref2{5};
    dodaj(tree, 10);
    dodaj(tree, 1);
    dodaj(tree, 2);
    std::cout<<tree;
    delete tree;
    return 0;
}