function main(input) {
	input = input.split("\n");
	const n = parseInt(input.shift());
	let ans = 0n;
	let sign = [];
	for(let i=0; i<n; i++) {
	    sign[i] = input[i][0] == '-' ? '-' : '+';
	    input[i] = input[i].indexOf('.') < 0 ? input[i] += '.' : input[i];
	    const dotLeft = BigInt(input[i].substr(0, input[i].indexOf('.'))) * 10000000000n;
	    const dotRight = BigInt(sign[i] + input[i].substr(input[i].indexOf('.') + 1).padEnd(10, '0'));
	    ans += (dotLeft + dotRight);
	}
	const str = ans.toString();
	const left = str.substr(0, str.length - 10);
	const right = str.substr(-10);
	console.log(left + "." + right);
}

main(require("fs").readFileSync("/dev/stdin", "utf8"));