gistfile1.txt

function fn1(arr) {
  if (arr.length === 1) {
    return arr[0];
  } else {
    return arr[0] + fn2(arr.slice(1));
  }
}

function fn2(arr) {
    if (arr.length === 1) {
    return arr[0];
  } else {
    return arr[0] + fn3(arr.slice(1));
  }
}

function fn3(arr) {
  if (arr.length === 1) {
    return arr[0];
  }
}

fn1([1,2,3]);