And Ken, this is Sameh. A lot of the supply chain issues have been across the rail industry, the trucking industry, a lot of industries. And a lot of it is bringing people back. Like we have been talking about congestion and all the rest here, the roller coaster of volume drops and increases. You go down about 30%, 40% this time last year, then you go up about 30%, 40% after, and you have to bring people back. It's not a trivial exercise. And trying to bring back also the assets like a lot of locomotives were stored we had to activate them. And when you look at the numbers, the GTMs as an example in Q2 compared to Q2 last year, they went up by 30%. The headcount and transportation went up by 8%. So 8% against 30% volume increase. The mechanical headcount went up by 3%. So, bringing people back is not a trivial exercise, and it did contribute for sure to some of this congestion. But at the same time, it does provide a nice productivity swing, because, if you recall, when we said, in PSR Phase 2, which was last year, we're very much oriented, obviously, towards making up for the loss revenue. And we said that in Phase 3, which is 2021, we don't want to lose all the gains that we made. So we did conserve a lot of the gains, because the headcounts are not going up at the same level as the volume increases. And the train length did not go down very much, it went down by about 2%, which means that the train starts and all the rest. We have conserved a lot of what we did last year, so the game really is how can you absorb the volumes, how can you improve the service, which was the thrust of Phase 1 of 2019, and we have done a lot of work in that area. We have really pushed the envelope on the local service and the industry jobs on this spotting and putting percentages, which went up from like, 70% to 87%. So, the game is how can you improve the service, absorb the volumes, and still maintain some of the efficiency gains that we have done. We are talking about locomotives, actually, 69 locomotives are going to leave our network in the next three weeks, leave the network, not go in storage. They are leaving the network, because a lot of the locomotives are actually demo locomotives that we're working on with the vendor. So, the efficiency is still there, but at the same time, the service is primordial. And this is really the balancing act that we are trying to do. And this is a challenge to the supply chain to your question.