// SNAKE AND LADDER
// Official Solution by Jacob Plachta

#define DEBUG 0

#include <algorithm>
#include <functional>
#include <numeric>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <complex>
#include <cstdlib>
#include <ctime>
#include <cstring>
#include <cassert>
#include <string>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <sstream>
using namespace std;

#define LL long long
#define LD long double
#define PR pair<int,int>

#define Fox(i,n) for (i=0; i<n; i++)
#define Fox1(i,n) for (i=1; i<=n; i++)
#define FoxI(i,a,b) for (i=a; i<=b; i++)
#define FoxR(i,n) for (i=(n)-1; i>=0; i--)
#define FoxR1(i,n) for (i=n; i>0; i--)
#define FoxRI(i,a,b) for (i=b; i>=a; i--)
#define Foxen(i,s) for (i=s.begin(); i!=s.end(); i++)
#define Min(a,b) a=min(a,b)
#define Max(a,b) a=max(a,b)
#define Sz(s) int((s).size())
#define All(s) (s).begin(),(s).end()
#define Fill(s,v) memset(s,v,sizeof(s))
#define pb push_back
#define mp make_pair
#define x first
#define y second

template<typename T> T Abs(T x) { return(x<0 ? -x : x); }
template<typename T> T Sqr(T x) { return(x*x); }
string plural(string s) { return(Sz(s) && s[Sz(s)-1]=='x' ? s+"en" : s+"s"); }

const int INF = (int)1e9;
const LD EPS = 1e-9;
const LD PI = acos(-1.0);

//#if DEBUG
#define GETCHAR getchar
/*#else
#define GETCHAR getchar_unlocked
#endif*/

bool Read(int &x)
{
	char c,r=0,n=0;
	x=0;
		for(;;)
		{
			c=GETCHAR();
				if ((c<0) && (!r))
					return(0);
				if ((c=='-') && (!r))
					n=1;
				else
				if ((c>='0') && (c<='9'))
					x=x*10+c-'0',r=1;
				else
				if (r)
					break;
		}
		if (n)
			x=-x;
	return(1);
}

bool ReadLL(LL &x)
{
	char c,r=0,n=0;
	x=0;
		for(;;)
		{
			c=GETCHAR();
				if ((c<0) && (!r))
					return(0);
				if ((c=='-') && (!r))
					n=1;
				else
				if ((c>='0') && (c<='9'))
					x=x*10+c-'0',r=1;
				else
				if (r)
					break;
		}
		if (n)
			x=-x;
	return(1);
}

#define MOD 1000000007

int main()
{
		if (DEBUG)
			freopen("in.txt","r",stdin);
	int T,t;
	LL N;
	int K;
	int i,ans;
	LL a,b,x,y;
	static pair<LL,int> P[1000];
	Read(T);
		Fox1(t,T)
		{
			ReadLL(N),Read(K);
				Fox(i,K)
					ReadLL(P[i].x),Read(P[i].y);
				if (K==2*N-1)
				{
					ans=1;
					goto Done;
				}
			sort(P,P+K);
			a=1,b=N;
				Fox(i,K-1)
					if ((P[i].x==P[i+1].x) && (P[i].x==a))
						a++;
				FoxR(i,K-1)
					if ((P[i].x==P[i+1].x) && (P[i].x==b))
						b--;
			ans=0;
				Fox(i,K-1)
					if ((P[i].x==P[i+1].x) && (P[i].x>=a) && (P[i].x<=b))
						goto Done;
			x=-1;
				Fox(i,K)
					if ((P[i].x>=a) && (P[i].x<=b))
						if (x<0)
							x=y=P[i].x;
						else
						{
								if ((P[i].x-y)%2==(P[i].y+P[i-1].y)%2)
									goto Done;
							y=P[i].x;
						}
				if (x<0)
				{
					N=b-a+1;
						if (N==1)
							ans=2;
						else
						{
							N=(N-1)%MOD;
							ans=(4+2*N*(N+1))%MOD;
						}
				}
				else
				{
					a=max(1LL,x-a);
					b=max(1LL,b-y);
					ans=2*(a%MOD)*(b%MOD)%MOD;
				}
Done:;
			printf("Case #%d: %d\n",t,ans);
		}
	return(0);
}