#include <stdio.h>

int height = 0; // = height of stair case
int numBricks = 0; // = num bricks needed to build staircase



void c_tri()
{
	while(0 < height)
	{
		numBricks = numBricks + height;
		height = height - 1;
	}
}

void asm_tri()
{
	asm("push eax \n\t"
	     "push ebx \n\t"

	     "mov ebx, 0 \n"
	     "mov eax, _height \n\t"

	     "WHILE:\n\t"
	     "cmp eax, 0 \n\t"
	     "jna DONE \n\t"
	     "add ebx, eax \n\t"
	     "sub eax, 1 \n\t"
	     "jmp WHILE \n"

	     "DONE: \n\t"
	     "mov _numBricks, ebx \n\t"

	     "pop ebx \n\t"
	     "pop eax");
}



int main(void)
{
	while(1)
	{
		printf("-> ");
		scanf("%d", &height);
		if (height < 0) break;
		asm_tri();
		printf("%d\n", numBricks);
	}
	printf("bye\n");
	return 0;
}