//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;
import std.conv;
void main() {
	uint length;
	readf("%d\n", &length);
	BigInt num;
	BigInt deci;

	for(uint i=0; i<length; i++) {
		char[] orig;
		readln(orig);

		BigInt biga;
		BigInt bigb;

		if(orig.canFind('.')) {
			char[] a, b;
			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];
			}

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

			biga = BigInt(a);
			bigb = BigInt(b);

			if(a[0] == '-')
				bigb *= -1;
		} else {
			char[] a;
			a.length = orig.length-1;
			for(int j=0; orig[j] != '\n'; j++)
				a[j] = orig[j];
			biga = BigInt(a);
			bigb = BigInt("0");
		}

		num += biga;
		deci += bigb;
	}

	BigInt ten = 10000000000;
	num += (deci / ten);
	deci -= ((deci / ten) * ten);
	/*char[] deciString = deci.toString("10d");
	int diff = deciString.le;
	deciString.length = 10;
	for(int i=diff; i<10;i++)
		deciString[i] = '0';*/
	char[] deciString;
	writef("%d.%010d\n", num, deci);
}