'use strict'
function Main(input) {
    input = input.split("\n");
    const text = input[0]
    const length = text.length
    for (let i = 0; i <= length / 2; i++) {
        const len = length / 2 - i
        const arr = text.slice(0, len)
        const searchTxt = text.slice(len)
        const reg = new RegExp(arr)
        if (searchTxt.search(reg) === 0 && arr.length * 2 !== length) {
            console.log(arr.length * 2)
            break
        }
    }
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));