Language: C

{-# LANGUAGE OverloadedStrings #-}
module Main where

import           Data.List
import           Control.Monad
import           Debug.Trace
import qualified Data.ByteString.Char8         as BC
import           Data.Maybe                     ( fromJust )
import qualified Data.Set                      as S
import qualified Data.IntMap.Strict            as IM
import qualified Data.Map.Strict               as M
import           Data.Char
import Data.Bits

modN = 1000000007


readTuple2 :: IO (Int, Int)
readTuple2 = do
    [a, b] <- map (fst . fromJust . BC.readInt) . BC.words <$> BC.getLine
    return (a, b)

readTuple3 :: IO (Int, Int, Int)
readTuple3 = do
    [a, b, c] <- map (fst . fromJust . BC.readInt) . BC.words <$> BC.getLine
    return (a, b, c)

readInt :: IO Int
readInt = fst . fromJust . BC.readInt <$> BC.getLine

readInts :: IO [Int]
readInts = map (fst . fromJust . BC.readInt) . BC.words <$> BC.getLine

split :: (a -> Bool) -> [a] -> [[a]]
split f [] = []
split f as =
    let (fo, la) = span f as
        las      = case la of
            [] -> []
            xs -> split f $ tail xs
    in  case fo of
            [] -> las
            xs -> xs : las

pow :: Int -> Int -> Int -> Int
pow base 1 modNum = base `mod` modNum
pow base time modNum
    | odd time = let 
        a = pow base (time `div` 2) modNum `mod` modNum
        in
        a * a * base `mod` modNum
    | otherwise = let
        a = pow base (time `div` 2) modNum `mod` modNum
        in
        a * a `mod` modNum

solve :: Integer -> Integer -> Integer
solve n k = let
    ketaCount k = sum [(n - k + 1)..n]  - sum [0..k-1] + 1
    in
    (`mod` modN) $ sum $ ketaCount <$> [k..n+1] 



main = do
    (n, k) <- readTuple2
    print $ solve (fromIntegral n)  (fromIntegral k)







Compiler output:
main.c:1:1: error: expected identifier or '(' before '{' token
    1 | {-# LANGUAGE OverloadedStrings #-}
      | ^
main.c:1:3: error: stray '#' in program
    1 | {-# LANGUAGE OverloadedStrings #-}
      |   ^
main.c:1:32: error: stray '#' in program
    1 | {-# LANGUAGE OverloadedStrings #-}
      |                                ^
main.c:2:1: error: unknown type name 'module'
    2 | module Main where
      | ^~~~~~
main.c:2:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'where'
    2 | module Main where
      |             ^~~~~
main.c:2:13: error: unknown type name 'where'
main.c:46:26: error: stray '`' in program
   46 | pow base 1 modNum = base `mod` modNum
      |                          ^
main.c:46:30: error: stray '`' in program
   46 | pow base 1 modNum = base `mod` modNum
      |                              ^
main.c:49:28: error: stray '`' in program
   49 |         a = pow base (time `div` 2) modNum `mod` modNum
      |                            ^
main.c:49:32: error: stray '`' in program
   49 |         a = pow base (time `div` 2) modNum `mod` modNum
      |                                ^
main.c:49:44: error: stray '`' in program
   49 |         a = pow base (time `div` 2) modNum `mod` modNum
      |                                            ^
main.c:49:48: error: stray '`' in program
   49 |         a = pow base (time `div` 2) modNum `mod` modNum
      |                                                ^
main.c:51:22: error: stray '`' in program
   51 |         a * a * base `mod` modNum
      |                      ^
main.c:51:26: error: stray '`' in program
   51 |         a * a * base `mod` modNum
      |                          ^
main.c:53:28: error: stray '`' in program
   53 |         a = pow base (time `div` 2) modNum `mod` modNum
      |                            ^
main.c:53:32: error: stray '`' in program
   53 |         a = pow base (time `div` 2) modNum `mod` modNum
      |                                ^
main.c:53:44: error: stray '`' in program
   53 |         a = pow base (time `div` 2) modNum `mod` modNum
      |                                            ^
main.c:53:48: error: stray '`' in program
   53 |         a = pow base (time `div` 2) modNum `mod` modNum
      |                                                ^
main.c:55:15: error: stray '`' in program
   55 |         a * a `mod` modNum
      |               ^
main.c:55:19: error: stray '`' in program
   55 |         a * a `mod` modNum
      |                   ^
main.c:59:48: error: too many decimal points in number
   59 |     ketaCount k = sum [(n - k + 1)..n]  - sum [0..k-1] + 1
      |                                                ^~~~
main.c:61:6: error: stray '`' in program
   61 |     (`mod` modN) $ sum $ ketaCount <$> [k..n+1]
      |      ^
main.c:61:10: error: stray '`' in program
   61 |     (`mod` modN) $ sum $ ketaCount <$> [k..n+1]
      |          ^