Given that 60, 154, 200 are divided by a certain natural number, the remainders are a-1, a**2, a**3-1 respectively, find the value of the natural number.
已知60，154，200被某自然数除所得的余数分别是a-1，a**2，a**3-1，求该自然数的值．
<result>29</result>