long mod=1e9+7,dp[3002][3002],W;
L[3000],R[3000],i,j;
main(n,m,k){
	scanf("%d%d%d",&n,&m,&k);
	for(dp[0][1]=1;~scanf("%d%d",L+j++,R+j););
	for(;i<k;i++){
		for(j=0;j++<n;)dp[i][j]=(dp[i][j]+dp[i][j-1])%mod;
		for(j=0;j<m;j++){
			dp[i+1][L[j]]+=W=dp[i][R[j]]-dp[i][L[j]-1];
			dp[i+1][R[j]+1]-=W;
		}
		for(j=0;j++<n;)dp[i+1][j]=(dp[i+1][j]+dp[i+1][j-1]+mod)%mod;
	}
	printf("%d",dp[k][n]);
}