Find sum of all the numbers that are multiples of 10 and are less than or equal to a given number "N". (quotes for clarity and be careful of integer overflow)

-----Input-----
Input will start with an integer T the count of test cases, each case will have an integer N.

-----Output-----
Output each values, on a newline.

-----Constraints-----
- 1 ≤ T ≤ 10
- 1 ≤ N ≤1000000000

-----Example-----
Input:
1
10

Output:
10

-----Explanation-----
Example case 1. Only integer that is multiple 10 that is less than or equal to 10 is 10

Source: codechef | Difficulty: UNKNOWN_DIFFICULTY


Solutions:
for t in range(eval(input())):
	n = eval(input())
	n -= n % 10
	n /= 10
	print(n * (n + 1) / 2 * 10)


def tenn():
	t = eval(input())
	for i in range(t):
		a = eval(input())
		r = a / 10
		t = r * (r + 1) / 2
		print(t * 10)
tenn()


t = int(input())
l = list()
for i in range(t):
	n = int(input()) / 10
	l.append(n)
for n in l:
	print(int(n * (n + 1) / 2.0 * 10))


def main():
	t = int(input())
	while t != 0:
		t = t - 1
		N = int(input())
		print(5 * int(N / 10) * (int(N / 10) + 1))
	return 0
main()


t = int(input())
while t:
	n = int(input())
	t -= 1
	r = n / 10
	r = 10 * (r * (r + 1)) / 2
	print(r)