How can I save to string the latest record's value? -Firebase DB, JS

I have a database, like the screenshoot attached:

Under the Input there are many childs with 1,2,3,4... names. In my program I want to get the latest child, with the input1,2 and 3 values. Here is the code I have:

const databaseRef = firebase.database().ref();
const inputRef = databaseRef.child("Input");

inputRef.orderByChild("dataAdded").limitToLast(1).once('value', snap => {
    console.log(snap.val());
  });

And the output is:

{116: {…}}

  116:

    input1: 5

    input2: 1

    input3: 1

How can I put the input1,2 and 3 values into strings?