Poker and Walk

<p> One day, Moat invited TeStatic to play poker at teaching building 9, and TeStatic was in teaching building 7 at that time. </p> <p> TeStatic has special walking habit. He will stop <span class="MathJax_Preview"></span><span class="MathJax" id="MathJax-Element-1-Frame"><span class="mrow" id="MathJax-Span-2"><span class="msubsup" id="MathJax-Span-3">T<span>0</span></span></span></span> seconds after every <span class="MathJax_Preview"></span><span class="MathJax" id="MathJax-Element-2-Frame"><span class="mrow" id="MathJax-Span-7">T</span></span> seconds' walking. We know that the distance between teaching building 7 and teaching building 9 is <span class="MathJax_Preview"></span><span class="MathJax" id="MathJax-Element-3-Frame"><span class="mrow" id="MathJax-Span-10">L</span></span> meters, and the speed of TeStatic when he walks is <span class="MathJax_Preview"></span><span class="MathJax" id="MathJax-Element-4-Frame"><span class="mrow" id="MathJax-Span-13">V</span></span> meters pre second. </p> <p> So, how much time that Moat had to wait? </p>

<p> In the first line of input file, there will be a positive integer <span class="MathJax_Preview"></span><span class="MathJax" id="MathJax-Element-5-Frame"><span class="mrow" id="MathJax-Span-16">T</span></span> , indicating the number of data set. <br /> Each data set contains a line with 4 integers <span class="MathJax_Preview"></span><span class="MathJax" id="MathJax-Element-6-Frame"><span class="mrow" id="MathJax-Span-19">V,T,T<span>0</span>,L</span></span> . The meaning of them has been stated in Problems Description. </p> <p> We guarantee that: <br /> <span class="MathJax_Preview"></span> <p class="MathJax_Display"> <span class="MathJax" id="MathJax-Element-7-Frame"><span class="mrow" id="MathJax-Span-30">1≤V≤10</span></span> </p> <p class="MathJax_Display"> <span class="MathJax"><span class="mrow"><span class="mo" id="MathJax-Span-36"></span>1≤T≤100</span></span> </p> <p class="MathJax_Display"> <span class="MathJax"><span class="mrow"><span class="mo" id="MathJax-Span-42"></span>1≤T<span>0</span>≤100</span></span> </p> <p class="MathJax_Display"> <span class="MathJax"><span class="mrow"><span class="mo" id="MathJax-Span-50"></span>1≤L≤1000</span></span> </p>

For each data set of input, print the time asked in second (rounded to 3 decimal places) in a line.