var Node = function(value) {
  this.value = value;
  this.left = null;
  this.right = null;
};


var treeSum = function(node, sum) {
  if (node === null) {
    return false;
  }

  if (node.left === null && node.right === null && node.value === sum) {
    return true;
  }

  var leftResult = treeSum(node.left, sum - node.value);
  var rightResult = treeSum(node.right, sum - node.value);

  return leftResult || rightResult;
};