这是一个 小人 从左边到右边移动的图案    但是我想知道 怎么让它从右边往左边移动

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
int main()
{
    int a , b;
    a=0;
    while (a<=10)
    {
        system("cls");
        b=1;
        while (b<=a)
        {
        printf(" ");
        b=b+1;
        }
        printf(" O\n");


        b=1;
        while (b<=a)
        {
            printf (" ");
            b=b+1;
        }
        printf("<H>\n");

        b=1;
        while (b<=a)
        {
        printf(" ");
        b=b+1;

        }
        printf("I I\n");
        Sleep(100);
            a=a+1;
    }
}