MOD = 998244353
class Bit:
    def __init__(self, n):
        self.size = n
        self.n0 = 1 << (n.bit_length() - 1)
        self.tree = [0] * (n + 1)
    
    def range_sum(self, l, r):
        return self.sum(r - 1) - self.sum(l - 1)
        
    def sum(self, i):
        i += 1
        s = 0
        while i > 0:
            s += self.tree[i]
            s %= MOD
            i -= i & -i
        return s
        
    def get(self, i):
        return self.sum(i) - self.sum(i - 1)
 
    def add(self, i, x):
        i += 1
        while i <= self.size:
            self.tree[i] += x
            self.tree[i] %= MOD
            i += i & -i
         
    def lower_bound(self, x):
        pos = 0
        plus = self.n0
        tot = 0
        while plus > 0:
            if pos + plus <= self.size and self.tree[pos + plus] < x:
                x -= self.tree[pos + plus]
                pos += plus
            plus //= 2
        return pos


n = int(input())
xy = []
for _ in range(n):
    x, y = map(int, input().split())
    xy.append((x - y, x + y))
    
if xy[0][0] < xy[-1][0]:
    px = 1
else:
    px = -1
    
if xy[0][1] < xy[-1][1]:
    py = 1
else:
    py = -1
    
xy = [(x * px, y * py) for x, y in xy]
sx, sy = xy[0]
gx, gy = xy[-1]
xy = xy[1:-1]
lst = []
se_y = {sy, gy}
for x, y in xy:
    if sx <= x <= gx and sy <= y <= gy:
        lst.append((x, y))
        se_y.add(y)

lst.sort(key = lambda x:(x[0], x[1]))
dic = {y:i for i, y in enumerate(sorted(se_y))}
l = len(dic)
sy = dic[sy]
gy = dic[gy]
bit = Bit(l)
bit.add(sy, 1)
for _, y in lst:
    y = dic[y]
    bit.add(y, bit.sum(y))
ans = bit.sum(gy) % MOD
print(ans)