n,k=map(int,input().split())
m=int(input())
p=[-1]*k
for _ in range(m):
  l,r=map(int,input().split())
  l-=1
  r-=1
  p[r]=max(p[r],l)
for i in range(k):
  for j in range(i+1,k):
    if i!=j and p[i]!=-1 and p[j]!=-1 and p[i]>=p[j]:
      p[j]=-1
M=998244353
q1=[[[0]*(k+1) for i in range(k+2)] for _ in range(2)]
q2=[[[0]*(k+1) for i in range(k+2)] for _ in range(2)]
for r in range(k):
  nq=[[0]*(k+1),[0]*(k+1)]
  if p[r]!=-1:
    l=p[r]
    nq[1][r-l+1]+=1
    for i in range(k+1):
      if i-(r-l+1)>=0:
        nq[0][i]+=q1[1][i-(r-l+1)][l-1]
        nq[1][i]+=q1[0][i-(r-l+1)][l-1]
    for i in range(k+1):
      nq[0][i]+=q2[1][i-1][r-1]-q2[1][i-min(r-l,r,i)-1][r-min(r-l,r,i)-1]
      nq[1][i]+=q2[0][i-1][r-1]-q2[0][i-min(r-l,r,i)-1][r-min(r-l,r,i)-1]
  for i in range(k+1):
    q1[0][i][r]=nq[0][i]+q1[0][i][r-1]
    q1[0][i][r]%=M
    q1[1][i][r]=nq[1][i]+q1[1][i][r-1]
    q1[1][i][r]%=M
    q2[0][i][r]=nq[0][i]+q2[0][i-1][r-1]
    q2[0][i][r]%=M
    q2[1][i][r]=nq[1][i]+q2[1][i-1][r-1]
    q2[1][i][r]%=M
a=pow(k,n,M)
for i in range(k+1):
  a-=pow(k-i,n,M)*q1[1][i][k-1]
  a+=pow(k-i,n,M)*q1[0][i][k-1]
  a%=M
print(a)