Angular JS - Update input options with other input options

HTML

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.0.7/angular.min.js"></script>
<div ng-controller="myCtrl" ng-app="myApp">
  <div>
    <select ng-model="selectedCountry" ng-options="country.name for country in countries" ng-change="changeChipping()">
    </select>
  </div>
  <div>
    <select ng-model="selectedCountry" ng-options="country.name for country in countries" ng-change="changeChipping()">
    </select>
  </div>
  
  Shipping costs: {{selectedCountry.shipping}}
</div>

JavaScript

var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope) {
    $scope.countries = [{
      	"name": "Freedonia",
      	"shipping" : "30"
      },{
      	"name": "Mordor",
      	"shipping": "70"
      },{
      	"name": "Oz",
      	"shipping": "100"
      }];
      
      $scope.selectedCountry = $scope.countries[0];
    
    //Bit required for ng-Cart directive
    $scope.changeShipping = function() { 	
      ngCart.setShipping ($scope.selectedCountry.shipping);
  };
 });