Adding 50 or subtracting 50 to a natural number is a perfect square number. Try to find the value of this natural number?
某自然数加50或减50，都是完全平方数，试求这个自然数的值？
<gadget id="calculator">26 ** 2</gadget>
<output>676</output>

<gadget id="calculator">676 - 50</gadget>
<output>626</output>

<result>626</result>