描述：给定字符串 num（非负整数）和整数 k，移除 k 位数字，使剩余数字最小。以字符串形式返回（不含前导零）。
Dan Simmons, the author of more than three dozen books, including the famed Hyperion Cantos, has died from a stroke. He was 77.
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Раскрыты подробности о договорных матчах в российском футболе18:01。关于这个话题，夫子提供了深入分析
Space Forge have sent a microwave-sized factory into orbit, and have demonstrated that its furnace can be switched on and reach temperatures of around 1,000C.