Zhang Fan's age this year (1994) is exactly equal to the sum of the four digits in the year he was born. Ask: What is his age?
张帆今年(1994年)的年龄正好等于他出生那年年号的四个数字之和，求：他的年龄是多少岁．
<gadget id="calculator">1_994 - 1_975</gadget>
<output>19</output>

<result>19</result>