Definition: In this task, you're given a short article. Your job is to classify the article based on its category. Use the following classification labels, 0. World, 1. Sports, 2. Business, 3. Science or Technical. Label the text "0" if it contains information related to world. Label the text "1" if it contains information related to sports. Label the text "2" if it contains information related business. Label the text "3" if it contains science or technical related information. 
Input: Citigroup Bond Trading Investigated by UK Regulator (Update1) Aug. 18 (Bloomberg) -- Citigroup Inc., the world #39;s biggest bank, is being investigated by the UK market regulator over unusual trading activity #39; #39; in European government bonds earlier this month. 
