function Compute(){
    return Promise.resolve(0)
           .then(function While(result){
              if(result > 0) return result;

              return Do1().then(function(result){
                  if(result > 1) {
                      return Do2().then(function(do2Result){
                        return While(result+do2Result);
                      });
                  }
                  return While(result);
              });
            });
}