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

E.sort(key=lambda x: (x[0], x[1]))
ans = 1
num = 0
for x, p in E:
    if p == 1:
        ans *= k - num
        ans %= mod
        num += 1
    else:
        num -= 1
print((pow(k, n, mod) - ans) % mod)