import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################

n, k = na()
eve = []
for _ in range(n):
    l,r = na()
    eve.append((l,1))
    eve.append((r,-1))
eve = sorted(eve)
ans = 1
z = 0
mod = 998244353
for x, i in eve:
    if i == 1:
        ans *= k - z
        ans %= mod
        z += 1
    else:
        z -= 1
    #print(x,i,z,ans)


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