//No.81 すべて足すだけの簡単なお仕事です。
import std.stdio;
import std.bigint;
import std.algorithm;
void main() {
	uint length;
	readf("%d\n", &length);
	BigInt num;
	BigInt deci;

	for(uint i=0; i<length; i++) {
		char[] a, b;
		char[] orig;
		readln(orig);
		if(orig.canFind('.')) {
			int j, pos = 0;
			for(j=0; orig[j] != '.'; j++) {
				a.length += 1;
				a[j] = orig[j];
			}
			for(j+=1; orig[j] != '\n'; j++) {
				b.length += 1;
				b[pos++] = orig[j];
			}
		} else {
			a.length = orig.length;
			a = orig;
			b.length = 10;
			b = ['0','0','0','0','0','0','0','0','0','0'];
		}


		long l = b.length;
		b.length = 10;
		for(long lon = l; lon<10; lon++) {
			b[lon] = '0';
		}


		BigInt biga = a;
		BigInt bigb = b;

		if(a[0] == '-')
			bigb *= -1;
		num += biga;
		deci += bigb;
	}


	BigInt ten = 10000000000;
	num += (deci / ten);
	deci -= ((deci / ten) * ten);
	writeln(num,'.',deci,'\n');
}