n = int(input())
P = []
for _ in range(n):
    x, y = map(int, input().split())
    x, y = x + y, x - y
    P.append([x, y])
mod = 998244353

class Fenwick_Tree:
    def __init__(self, n):
        self.n = n
        self.data = [0] * n

    def add(self, p, x):
        p += 1
        while p <= self.n:
            self.data[p - 1] += x
            self.data[p - 1] %= mod
            p += p & -p

    def sum(self, l, r):
        '''範囲[l, r)(lからr-1まで)の総和を求める'''
        return (self._sum(r) - self._sum(l)) % mod

    def _sum(self, r):
        '''範囲[0, r)(0からr-1まで)の総和を求める'''
        s = 0
        while r > 0:
            s += self.data[r - 1]
            s %= mod
            r -= r & -r
        return s

if P[0][0] > P[-1][0]:
    for i in range(n):
        P[i][0] *= -1
if P[0][1] > P[-1][1]:
    for i in range(n):
        P[i][1] *= -1

from bisect import bisect_left
def compression(lst):
    sort_lst = sorted(set(lst))
    compression_lst = [None for _ in range(len(lst))]
    ele2ind_dict = dict()
    for i, ele in enumerate(lst):
        compression_lst[i] = bisect_left(sort_lst, ele)
        ele2ind_dict[ele] = compression_lst[i]
    return sort_lst, compression_lst, ele2ind_dict

Y = [P[i][1] for i in range(n)]
_, _, ele2ind_dict = compression(Y)
Y = [ele2ind_dict[Y[i]] for i in range(n)]
for i in range(n):
    P[i][1] = Y[i]
PP = []
for i in range(n):
    x, y = P[i]
    if P[0][0] <= x <= P[-1][0] and P[0][1] <= y <= P[-1][1]:
        PP.append((x, y))
PP.sort(key=lambda x: (x[0], x[1]))

DP = Fenwick_Tree(len(set(Y)))
DP.add(PP[0][1], 1)
for i in range(1, len(PP) - 1):
    DP.add(PP[i][1], DP._sum(PP[i][1] + 1))
print(DP._sum(PP[-1][1] + 1))