Investigate whether 120 kinds of foods contain vitamins A, B, and C. The results are: 62 kinds contain A, 90 kinds contain B, and 68 kinds contain C; 48 kinds contain A and B, and 36 kinds contain A and C species, including 50 species of B and C; 25 species of A, B and C. Q There are ----- species that only contain vitamin A.
对120种食物是否含有维生素甲、乙、丙进行调查，结果是：含甲的62种，含乙的90种，含丙的68种；含甲、乙的48种，含甲、丙的36种，含乙、丙的50种；含甲、乙、丙的25种．问仅含维生素甲的有-----种．
<gadget id="calculator">25 - 48 - 36</gadget>
<output>-59</output>

<gadget id="calculator">62 + (-59)</gadget>
<output>3</output>

<result>3</result>