1.已知圆x2+y2=1x^{2}+y^{2}=1x2+y2=1与抛物线y2=2px(p>0)y^{2}=2px(p>0)y2=2px(p>0)交于AAA,BBB两点,与抛物线的准线交于CCC,DDD两点,若四边形ABCDABCDABCD是矩形,则ppp等于((( )))