var s = require("fs").readFileSync("/dev/stdin", "utf8")

	while(s.length) {

		s = s.slice(0, -1)
		l = s.length

		if(l%2 == 0) {
			if(s.slice(0, l/2) == s.slice(l/2)) {
				console.log(l)
				return;
			}
		}

	}
