Arrange the four-digit numbers composed of exactly two different numbers in ascending order to get 1000, 1001, 1010, ..., 9997, 9998, then what is the 200th number in this column.
将恰由两个不同数字组成的四位数从小到大的顺序排列起来得到1000，1001，1010，…，9997，9998，那么这列数中的第200个数是多少．
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