import java.io.FileNotFoundException;
import java.math.BigDecimal;
import java.util.Arrays;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws FileNotFoundException {
		long t = System.currentTimeMillis();
		new Main().run();
		System.err.println(System.currentTimeMillis() - t);
	}
	
	
	
	void run() {
		Scanner sc = new Scanner(System.in);
		int N=sc.nextInt();
		BigDecimal ret=new BigDecimal(0);
		for(int i=0;i<N;++i) {
			BigDecimal a=new BigDecimal(sc.next());
			ret=ret.add(a);
		}
		String str=ret.toString();
		int p=0;
		while(p<str.length()&&str.charAt(p)!='.')++p;
		if(p!=str.length()) {
			int n=str.length();
			for(int i=0;i<10-(n-1-p);++i) str=str+"0";
		}else {
			str=str+".";
			for(int i=0;i<10;++i)str=str+"0";
		}
		System.out.println(str);
	}


	static void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}

}