# 余事象を求める. (つまり, 全部被らない)

mod = 998244353

n,k = map(int,input().split())
ins = [0 for i in range(200003)]
outs = [0 for i in range(200003)]

for i in range(n):
	l, r = map(int,input().split())
	ins[l] += 1
	outs[r] += 1

now = 0
ans = 1

for i in range(200002):
	for j in range(outs[i]):
		now -= 1
	for j in range(ins[i]):
		ans *= k-now
		ans %= mod
		now += 1

print((pow(k, n, mod) - ans) % mod)