Where on earth do you get 12 kg watermelons? Genuine curious, the ones imported here in Denmark I would guess are big if they're around 3 kg.
Am from the Southeastern United States.
Before making a guess, try to weight them. I have hard time imagining watermelon (watermelon is the green thing unlike yellow melon) with only 3kg :) Your full water kettle already weights 2+kg.
$ units
You have: 1 watermelon
You want: grapes
* 907.19
/ 0.0011023 $ units
You have: 1 VIM user
You want: Emacs users
St4ck 0verflow...Regardless, I guess the OP just needs to find a better grocer, local "fruit mongers" up here in frigid Sweden certainly routinely handle watermelons that are way bigger than 3 kg. :)
1: https://www.whataboutwatermelon.com/index.php/2018/08/how-he...