Epic sprint P98503

When walking on the windy isle of Papa Stour, professor Oak broke his walking boats and his backpack, and the wind blew away his map of the isle and his camera cap. Furthermore, he only could recover his hat, also blown away by the wind, after an epic sprint.

Let us model the last situation. Assume a flat world, where the hat and Prof. Oak are points. At time 0 the hat starts moving away from Prof. Oak along a fixed direction, with constant acceleration a. At time r Prof. Oak starts running after his hat at constant speed s. Will he be able to catch it?

Input

Input consists of several cases, each one with a, s and r. All given numbers are integers between 1 and 10⁴.

Output

For every case, print “yes” if Prof. Oak can recover his hat, and “no” otherwise.