Contribution
Donation
noun, verbal noun
If you approach a building and attach some stuff to it, you're making a contribution. They get to keep it, after all.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
毎年少しだけ、母校へお金を寄付しています。
I contribute a little money to my alma mater every year.