n, k = map(int, input().split())
LR = [list(map(int, input().split())) for _ in range(n)]
LR.append([10**6, 10**6 + 1])
mod = 998244353

P = [k % mod for _ in range(n + 1)]
for i in range(1, n + 1):
    P[i] = P[i - 1] * (k - i) % mod

LR.sort(key=lambda x: (x[1], x[0]))
ans = 0
num = 0
res = 0
l, r = -1, -1
for i in range(n + 1):
    if l == -1 and r == -1:
        l, r = LR[i]
        r -= 1
        num += 1
    elif r < LR[i][0]:
        if num > 1:
            if ans == 0:
                ans = 1
            ans *= (pow(k, num, mod) - P[num]) % mod
            ans %= mod
        else:
            res += 1
            l, r = LR[i]
            r -= 1
        num = 1
    else:
        l = min(l, LR[i][0])
        r = max(r, LR[i][1] - 1)
        num += 1
    if i == n - 1:
        ans *= pow(k, res, mod)
        ans %= mod
print(ans)