Nuclear missiles are heading your way. You must respond. What now?

Such a shame they do not accept bottle caps.

300 nuclear missiles are heading your way. You must respond. What now?

Assuming a full international exchange from all the nuclear powers, I would put on some noise cancelling headphones, get in the basement and hope none of the compression waves or fallout comes my way. I assume all of the world's economies would collapse and those that survive go back to the grass age with hunter gatherer lifestyles and maybe some lucky ones go agrarian. People mistakenly reflect on how things went for Japan but that was just two tiny single-warhead nukes.

Otherwise I assume others here have also stocked up on painters suits, duct tape, full face masks, P3-100 filters, water, lots of water, more water, freeze dried foods, wood, etc...