 So k plus q by this distance plus k minus q by that distance, so it becomes 0. Sir, if we like this, we can put this. It can't be both curvatures. Only once and then each curvatures are this. Sir, if we like this, we can put this. It will be same? Exactly same. Exactly same? No. That's all right. It will be same? Yes. What do you think? The way I did this, I distributed on this ring. q charge is uniformly distributed on the ring of radius r. It's a point charge, right? It's a small charge. No strings. Yeah. So this will be... So any charge distribution is potential at a distance z, radius is r, or a charge is q. The ring is like this and you're finding along this line. It's a ring. A ring.