#include <stdio.h>

typedef struct node {
	int data;
	struct node *left, *rite;
} tree;

tree* node(int k) {
	tree *temp = (tree*) malloc(sizeof(tree), 1);
	temp->left = temp->rite = 0;
	temp->data = k;
	return(temp);
}

int main(int argc, char* argv[]) {
	int n;
	tree *root = 0;

	while(scanf("%d", &n) != EOF)
		insert(node(n), &root);

	inorder(root);
	printf("\n");
}

int insert(tree *new, tree **cpp) {
	tree *cp = *cpp;
	if (!cp)
		*cpp = new;
	else
		insert(new, &(new->data < cp->data ? cp->left : cp->rite));
}
	
int inorder(tree *curr) {
	if (curr) {
		inorder(curr->left);
		printf("%d ", curr->data);
		inorder(curr->rite);
	}
}