const getGets = (arr) => {
  let index = 0;

  return () => {
    const toReturn = arr[index];
    index += 1;
    return toReturn;
  };
};
// this is the test
const test = ['3'];

const gets = this.gets || getGets(test);
const print = this.print || console.log;

let value = gets();

let sum = 0;
let valueCleared = 0;
let finalSum = 0;

const crooked = (n) => {
  let arr = n
    .replace(/\D/g, '')
    .split('')
    .map(Number);

  do {
    sum = arr.reduce((acc, el) => {
      acc += el;

      return acc;
    });

    arr = sum.toString().split('').map(Number);
  } while (arr.length > 1);

  return sum;
};

print(crooked(value));