A_Large.hs

import Control.Monad(forM_)
import Text.Printf

main :: IO()
main = do
  txt <- getContents
  let ls = lines txt
      num = head ls
      ps = mklist $ tail ls
  forM_ (zip ps [1..(length ps)]) $ \(p,i) ->
    printf "Case #%d: %d\n" i (solve p)
  --forM_ ps (putStrLn . show . solve)

--solve :: [Int] -> Int
solve [r,t] = proc' 1 (t `div` r)
  where
    proc' lef rig = case rig - lef of
      d
        | (abs d) <= 1 -> lef
      _ -> let m = (lef + rig) `div` 2
               sq = 2*(m^2) + (2*r-1)*m
           in if sq <= t then proc' m rig
              else proc' lef m

mklist :: [String] -> [[Integer]]
mklist xs = map (map read . words) xs