Xiao Ming and Xiao Qiang played a number game, Xiao Ming chose a number x (between 0-9), and then said: "I am considering a three-digit number (the hundreds digit is allowed to be 0), and the hundreds digit of this three-digit number is x, the tens digit is 3, and it is divisible by 11, please find the unit digit of this three-digit number." Xiaoqiang was very happy because he knew the law of numbers divisible by 11. But after thinking about it, he found that such a three-digit number does not exist. Then x = how much.
小明和小强玩了一个数字游戏，小明选择了一个数字x(0-9之间)，然后说："我正在考虑一个三位数(百位允许为0)，这个三位数的百位为x，十位为3，并且能被11整除，请你找出这个三位数的个位数．"小强非常开心，因为他知道能被11整除的数的规律．但是他思考后发现这样的三位数不存在．则x=多少．
<gadget id="calculator">1 - 0</gadget>
<output>1</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<result>4</result>