#include<bits/stdc++.h>
using namespace std;
#define LL long long
#define PII pair<int, int>

const int N = 1e5 + 10, mod = 1e9 + 7;
namespace IO
{
	char buf[1 << 21], *p1 = buf, *p2 = buf;
	inline char gc()
	{
		if(p1 == p2) p2 = (p1 = buf) + fread(buf, 1, 1 << 21, stdin);
		return p1 == p2 ? EOF : *p1++;
	}
	inline int read()
	{
		int f = 1, w = 0;
		char ch = gc();
		while(ch < '0' || '9' < ch)
		{
			if(ch == '-') f = -1;
			ch = gc();
		}
		while('0' <= ch && ch <= '9')
		{
			w = (w << 1) + (w << 3) + (ch ^ 48);
			ch = gc();
		}
		return f * w;
	}
	char obuf[1 << 21], *p3 = obuf;
	inline void pc(char c)
	{
		p3 - obuf <= 1 << 20 ? *p3++ = c : (fwrite(obuf, p3 - obuf, 1, stdout), p3 = obuf, *p3++ = c);
	}
	inline void write(int x)
	{
		if(x < 0) pc('-'), x = -x;
		if(!x) pc('0');
		static char c[50];
		static int tt;
		while(x) c[++tt] = x % 10 ^ 48, x /= 10;
		while(tt) pc(c[tt--]);
	}
}
using namespace IO;
int n, m, v, ans;
PII a[N];

LL ksm(LL x, LL y)
{
	LL res = 1;
	x %= mod;
	while(y)
	{
		if(y & 1) res = res * x % mod;
		y >>= 1;
		x = x * x % mod;
	}
	return res;
}

int main()
{
	freopen("assign.in", "r", stdin);
	freopen("assign.out", "w", stdout);
	
	int T = read();
	while(T--)
	{
		n = read(), m = read(), v = read();
		for(int i = 1; i <= m; i++) 
			a[i].first = read(), a[i].second = read();
		sort(a + 1, a + m + 1);
		m = unique(a + 1, a + m + 1) - a - 1;
		bool flag = 1;
		for(int i = 1; i < m; i++)
			if(a[i].first == a[i + 1].first)
			{
				flag = 0;
				break;
			}
		if(!flag)
		{
			puts("0");
			continue;
		}
		
		ans = ksm(1ll * v * v, a[1].first - 1) * ksm(1ll * v * v, n - a[m].first) % mod;
		for(int i = 1; i < m; i++)
			ans = ans * (ksm(1ll * v * v, a[i + 1].first - a[i].first) - ksm(v, a[i + 1].first - a[i].first - 1) * (v - 1) % mod + mod) % mod;
		printf("%d\n", ans);
	}
	return 0;
}