# https://yukicoder.me/problems/no/2197

import math

MOD = 998244353

def main():
    N, K = map(int, input().split())
    lr = []
    max_r = 0
    for _ in range(N):
        l, r = map(int, input().split())
        lr.append((l, r))
        max_r = max(max_r, r)

    in_events = [[] for _ in range(max_r + 1)]
    out_events = [0 for _ in range(max_r + 1)]
    for l, r in lr:
        in_events[l].append(r)
    
    visit_num = 0
    ans = 1
    for i in range(max_r + 1):
        # out
        visit_num -= out_events[i]

        # in 
        for r in in_events[i]:
            ans *= (K - visit_num)
            ans %= MOD
            visit_num += 1
            out_events[r] += 1
    
    answer = pow(K, N, MOD)
    answer -= ans
    answer %= MOD
    print(answer)








if __name__ == "__main__":
    main()