A sequence of all natural numbers whose second digit (from left to right) is 1, is written in strictly increasing order without repetition as follows. $$11, 21, 31, 41, 51, 61, 71, 81, 91, 110, 111, \ldots$$ Note that the first term of the sequence is 11. The third term is 31, eighth term is 81 and tenth term is 110. The 100th term of the sequence will be