n,k = map(int,input().split())
mod = 998244353 

arr = []
for i in range(n):
    l,r = map(int,input().split())
    arr.append((l,1,i))
    arr.append((r,0,i))
arr.sort()
cnt = 0
ans = 1
for x,io,l in arr:
    if io == 1:
        ans *= k-cnt
        ans %= mod
        cnt += 1
    else:
        cnt -= 1
print((pow(k,n,mod)-ans) % mod)