n,k = map(int,input().split())
mod = 998244353
lr = []
for i in range(n):
  l,r = map(int,input().split())
  lr.append([l, 1])
  lr.append([r, -1])

lr.sort()
ans = 1
now = 0
for a,b in lr:
  if b == -1:
    now -= 1
  else:
    ans *= k-now
    now += 1
  ans %= mod

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