If you have more than one number, it is recommended to use one number to synthesize the Christmas stocking, and then the other numbers to give to the number that has the Christmas stocking on it.
Then synthesize the glacier background.
Glacier Background Recipe:
15 Hat Cards + 15 Sock Cards + 15 Tree Cards + 2 Telescope Microscopes = Glacier Background
Action:
Security Room +2% Protection
The background can be used permanently.
1 Microscope + 5 Sock Cards + 5 Hat Cards + 5 Tree Cards = Christmas Stocking
Additionally there is a chance of opening a telescope for Christmas gifts.
Christmas Stocking Role: You can give each other Christmas gifts rewarded by EMS quests. There is a limit of 30 per day.
One Christmas stocking can be given 30 times, which means you can give 30 Christmas gifts to the big one with the small one. However, you can only send gifts that are not opened, and you can't send cards and binoculars that are opened.
If you want to use Christmas hats, Christmas trees, and Christmas socks to synthesize something, you can only experiment, there is no recipe.