var input = require("fs").readFileSync("input.txt").toString();
var nums = input.split("\n").filter(a=>(a)).map(a=>(parseInt(a)));
var seen = {};
var total = 0;
while(true){
	for(var i of nums){
		total += i;
		if(!seen[total]){
			seen[total]=1;
		}
		else{
			console.log(total);
			return 0;
		}
	}
}