There are two colored ribbons, one is 28 decimeters long and the other is 35 decimeters long. Now we need to cut these two colored ribbons into several small pieces of the same length. What is the longest length of each small piece?
有两根彩带，一根长28分米，另一根长35分米，现在要把这两根彩带剪成同样长的若干小段，剪成的每小段最长是多少分米．
<result>7</result>