문제

Fisherman Šime caught N tunas last night. With the help of a special app, he offerred them for sale to a famous Japanese company that specializes in purchasing quality fish. In what way does the app estimate the value, or the price, of a tuna? Based on the photo of the tuna, the app returns two estimated values, $P_{1}$ and $P_{2}$. If the difference between the estimates is less than or equal to X, then the higher value is taken. If the difference is strictly larger than X, the app returns a third estimate $P_{3}$ and then that estimate is taken as the final value of the tuna. Write a programme that will, based on the given estimates (sometimes two, sometimes three of them) for each of N tunas, output the total value of caught tunas.

입력

The first line of input contains the integer N (1 ≤ N ≤ 20), the number of tunas from the task. The second line of input contains the integer X (1 ≤ X ≤ 10), the number from the task. Then, N blocks follow in one of the two following forms: ● In one line, two integers $P_{1}$ and $P_{2}$ (1 ≤ $P_{1}$, $P_{2}$ ≤ 100) from the task, or ● In one line, two integers $P_{1}$ and $P_{2}$ (1 ≤ $P_{1}$, $P_{2}$ ≤100) from the task, and in the second line integer $P_{3}$ (1 ≤ $P_{3}$ ≤ 100) from the task.

출력

The first and only line of output must contain the total value of caught tunas.

예제 입력 1

5
2
3 4
2 1
5 3
4 4
4 2

예제 출력 1

19

예제 입력 2

4
2
3 5
2 8
4
6 5
6 3
7

예제 출력 2

22

예제 입력 3

3
10
20 50
30
20 40
50
70 20
10

예제 출력 3

90