// This DJ program outputs the sum 1 + 2 + ... + 100
class Summer extends Object {
    
  // This method returns the sum 0 + 1 + .. + n
  nat sum(nat n) {
    nat toReturn;
    // note: nat variables automatically get initialized to 0
      
    for(0; 0<n; n=n-1) { toReturn = toReturn + n; };

    toReturn;
  }
}

main {
  // create a new object of type Summer
  Summer s;
  s = new Summer();

  // print the sum 0 + 1 + ... + 100
  printNat( s.sum(100) );
}