The average of the three numbers A, B, and C is 97. It is known that the number of A is 107, and the number of B is 91. What is the number of C?
甲乙丙三个数的平均数是97，已知甲数为107乙数为91丙数为多少．
<gadget id="calculator">97 * 3</gadget>
<output>291</output>

<gadget id="calculator">291 - 107 - 91</gadget>
<output>93</output>

<result>93</result>