# intersecting intervals

Name the interval with the least left end point $I_1$. There are at most six intervals that may share a point with it. So we have at least 43 which have no point common with $I_1$. Of those, name the interval with the least left end point $I_2$. Again are at most six intervals that may share a point with $I_2$, leaving 36 that have no point either of the two named. We continue getting $I_3$ from 28 and so fourth until we get $I_8$ from 8.