series of numbers, the first number is 480, the second number is 400, starting from the third number, each number is the average of the previous two numbers. What is the integer part of the thousandth number?
一数列，第一个数为480，第二个数为400，从第三个数开始，每个数是它前面两个数的平均数．求第一千个数的整数部分是多少？
<result>426</result>