N,K = map(int,input().split())
l = []
for _ in range(N):
    L,R = map(int,input().split())
    l.append((L,1))
    l.append((R,-1))

l.sort()
tmp = 1
num = 0
P = 998244353
for t,i in l:
    if i == 1:
        tmp *= (K - num)
        tmp %= P
        num += 1
    else:
        num -= 1
ans = pow(K,N,P) - tmp
print(ans%P)