tell me the total number of items in an array deeply nested in an object?

 const items = [
    {
        id: "1",
        name: "a",
        sub: [
            {
                id: "1#1",
                name: "b",
                sub_sub: [
                    { id: "1#1#1", name: "b-a" },
                    { id: "1#1#2", name: "b-b" },
                ]
            },
            {
                id: "1#2",
                name: "c",
                sub_sub: [
                    { id: "1#2#1", name: "c-a" },
                ]
            },
        ]
    },
    {
        id: "2",
        name: "d",
        sub: [
            {
                id: "2#1",
                name: "e",
                sub_sub: [
                    { id: "1#2#1", name: "e-a" },
                ]
            }
        ]
    },
]

items.forEach(el => {
  const count = el.sub.reduce((total, curr) => total + curr.sub_sub.length, 0);
  console.log(count);
});