Prueba para el juez

main.cpp

#include <iostream>
#include <string>
using namespace std;

int main(){
   string str;
   while(cin >> str)
	  cout << str << endl;
}

main.hs

main = do
  [a, b] <- (map read . words) `fmap` getLine
  print (a+b)

procfile

{
  compile : "ghc -v0 -O main.hs",
  eval : "./main"
}