Start with a couple billion...

...it's easy to give some away, as Rob Wile explains in this Time article:

The Giving Pledge, the foundation created in 2010 by Bill and Melinda Gates and Warren Buffett to use their fortunes to solve the world's problems, has added fourteen new billionaire members.
The Pledge encourages the world's wealthiest individuals and families to give the majority of their wealth away to philanthropic causes. The foundation announced this week that fourteen more individuals or couples, hailing from Australia, China, Cyprus, Monaco, Norway, Slovenia, Tanzania, and the United States, have agreed to pledge. The newest signatories include easyJet founder Sir Stelios Haji-Ioannou; Harry Stine, said to be the richest man in Iowa; and Mohammed Dewji, the heir to the fortune of METL, the largest company in Tanzania.
Quartz calculated the net worth of eight of the fourteen new signatories (the only ones publicly available), and found they are sitting atop a combined fifteen billion dollars.

Here are the fourteen new names signing the Giving Pledge:

Leonard H. Ainsworth — Australia
Mohammed Dewji — Tanzania
Dagmar Dolby — United States
Dong Fangjun — People’s Republic of China
Anne Grete Eidsvig and Kjell Inge Røkke — Norway
Sir Stelios Haji-Ioannou — Monaco, Cyprus
Nick and Leslie Hanauer — United States
Iza and Samo Login — Slovenia
Dean and Marianne Metropoulos — United States
Terry and Susan Ragon — United States
Nat Simons and Laura Baxter-Simons — United States
Robert Frederick Smith — United States
Harry H. Stine — United States
You Zhonghui — People’s Republic of China

“Philanthropy is different around the world, but almost every culture has a long-standing tradition of giving back,” Melinda Gates, co-chair of the Bill & Melinda Gates Foundation, said in a statement. “Bill and Warren and I are excited to welcome the new, very international group of philanthropists joining the Giving Pledge, and we look forward to learning from their diverse experiences.”
The philanthropists will use their resources to support a range of causes, including climate change, environmental and ecological protection, education, poverty alleviation, and medical and healthcare research, the foundation said. Giving Pledge members are also meeting this week for the group’s annual two-day learning conference. Topics discussed include criminal justice reform, early childhood education, refugee aid, public health, and poverty alleviation.

Rico says it's a problem he wishes he had...