Question: Sofia Kovalevskaya was born in Russia in 1850. When she was 17, she traveled 2,500 kilometers from Moscow to Heidelberg, Germany, because girls were not allowed to study math in Russia at the time. When she was 33, she moved another 1,750 kilometers to Stockholm, Sweden, to teach math at a university. How many kilometers did Sofia travel to get from Moscow to Heidelberg to Stockholm?