Two iron wires are 65 meters and 91 meters long respectively. Use several pieces of the same rope to measure them respectively, and there is nothing left. What is the maximum length of such a rope?
两根铁丝分别长65米和91米，用若干根相同的绳子分别测量它们，都恰好量完无剩余，这样的一根绳子最多有多长？
<result>13</result>