Problem Statement
We have a sequence ~A~ consisting of integer pairs. Initially, ~A = ( (0, 1), (1, 0) )~ .
You may perform the following operation on ~A~ as many (possibly zero) times as you want:
- choose adjacent two integer pairs ~(a, b)~ and ~(c, d)~ , and insert ~(a + c, b + d)~ between them.
For a sequence ~T~ consisting of integer pairs, let us define ~f(T)~ as follows:
- let ~f(T) =~ (the minimum number of operations required to make every element of ~T~ contained in ~A~ ).
- We say that "every element of ~T~ is contained in ~A~ " if, for all elements ~x~ contained in ~T~ , ~x~ is contained in (the set consisting of the elements contained in ~A~ ).
- Here, if there are no such operations, let ~f(T) = 0~ .
There is a sequence ~S = ((a_1, b_1), (a_2, b_2), \dots, (a_N, b_N))~ consisting of ~N~ integer pairs. Here, all elements of ~S~ are pairwise distinct.
There are ~\frac{N \times (N+1)}{2}~ possible consecutive subarrays ~S_{l,r}=((a_l,b_l),(a_{l+1},b_{l+1}),\dots,(a_r,b_r))~ of ~S~ . Find the sum, modulo ~998244353~ , of ~f(S_{l,r})~ over those subarrays.
Formally, find ~\displaystyle \sum^{N} _ {l=1} \sum^{N} _ {r=l} f(S_{l,r})~ , modulo ~998244353~ .
Constraints
- ~1 \le N \le 10^5~
- ~0 \le a_i,b_i \le 10^9~
- ~a_i \neq a_j~ or ~b_i \neq b_j~ , if ~i \neq j~ .
Input
The input is given from Standard Input in the following format:
~N~
~a_1~ ~b_1~
~a_2~ ~b_2~
~\dots~
~a_N~ ~b_N~
Output
Print the answer as an integer.
Sample Input 1
7
1 2
3 7
3 5
0 0
1000000000 1
0 1
6 3
Sample Output 1
3511324
- ~f(S_{1,1})=2~ .
- We can make ~((0,1),(1,0)) \rightarrow ((0,1),(1,1),(1,0)) \rightarrow ((0,1),(1,2),(1,1),(1,0))~ .
- ~f(S_{1,2})=5~ .
- ~f(S_{1,3})=7~ .
- ~f(S_{2,2})=5~ .
- ~f(S_{2,3})=7~ .
- ~f(S_{3,3})=4~ .
- ~f(S_{5,5})=1000000000 = 10^9~ .
- ~f(S_{5,6})=1000000000 = 10^9~ .
- ~f(S_{6,6})=0~ .
- ~(0, 1)~ is originally contained in ~A~ .
- ~f(S_{l,r})=0~ for all ~S_{l,r}~ not mentioned above.
- We can prove that ~A~ can never contain ~(0,0)~ or ~(6,3)~ regardless of operations.
Therefore, the sum of ~f(S_{l,r})~ is ~2000000030 = 2 \times 10^9 + 30~ , whose remainder when divided by ~998244353~ is ~3511324~ .
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