func main()
	var N: int :: cui@input().toInt(&)
	var sum: []int :: #[30]int
	for(1, N)
		var _: [][]char :: cui@input().split(".")
		var isNegative: bool :: _[0][0] = '-'
		var num: []int :: #[^sum]int
		var digit: int :: ^_[0] - (isNegative ?(1, 0))
		for i(0, digit - 1)
			do num[9 + digit - i] :: _[0][(isNegative ?(1, 0)) + i] $ int - '0' $ int
		end for
		if(^_ = 2)
			for i(0, ^_[1] - 1)
				do num[9 - i] :: _[1][i] $ int - '0' $ int
			end for
		end if
		for i(0, ^num - 1)
			do sum[i] :+ (isNegative ?(-1, 1)) * num[i]
		end for
	end for
	for i(0, ^sum - 2)
		if(sum[i] < 0)
			do sum[i + 1] :- (sum[i].abs() / 10 + 1)
			do sum[i] :+ (sum[i].abs() / 10 + 1) * 10
		end if
		if(sum[i] >= 10)
			do sum[i + 1] :+ sum[i] / 10
			do sum[i] :% 10
		end if
	end for
	if(sum[^sum - 1] = -1)
		do cui@print("-")
		for i(0, ^sum - 1)
			do sum[i] :* -1
		end for
		for i(0, ^sum - 2)
			if(sum[i] < 0)
				do sum[i + 1] :- (sum[i].abs() / 10 + 1)
				do sum[i] :+ (sum[i].abs() / 10 + 1) * 10
			end if
			if(sum[i] >= 10)
				do sum[i + 1] :+ sum[i] / 10
				do sum[i] :% 10
			end if
		end for
	end if
	do sum.reverse()
	var f: bool :: true
	for i(0, 29)
		if(i < 19 & f & sum[i] = 0)
			skip i
		end if
		do f :: false
		do cui@print("\{sum[i]}")
		if(i = 19)
			do cui@print(".")
		end if
	end for
end func