#include <stdio.h>

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

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

	while(scanf("%d", &n) != EOF) {
		cpp = &root;
		while (cp = *cpp)
			cpp = &( n <= cp->data ? cp->left : cp->rite);

		cp = *cpp = (tree*) malloc(sizeof(tree), 1);
		cp->left = cp->rite = 0;
		cp->data = n;
	}

	inorder(root);
	printf("\n");
}
	
int inorder(tree *curr) {
	if (curr) {
		inorder(curr->left);
		printf("%d ", curr->data);
		inorder(curr->rite);
	}
}