Who tried for 24 years before he obtained permission from German authorities to "do something" to the Reichstag in Berlin? What did he want to do?

After Michael Cullen, a Berlin historian, sent them a postcard in 1971 suggesting that they wrap the Reichstag, Christo and Jeanne-Claude (renown artists) worked for 24 years to seek permission from the German parliament.
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Christo it is, Mozart ! (See?! I remembered this time who answered the question.)