var app = new Vue({
		  el: '#app',
		  data: {
		    value: '',
				msg: ''
		  },
		  methods: {
		    input() {
		     let val = ''
				 try{
					 val = eval(this.value)
				 } catch {
					 val = this.value
				 }
				 this.msg = val
		    }
		  }
		})