#include <algorithm>
#include <cstdio>
#include <cstring>
#include <utility>
#define PROB "assign"
namespace FIO {
	constexpr int ReadBufSz = 1048576;
	constexpr int WriteBufSz = 1048576;
	char ReadBuf[ReadBufSz];
	char WriteBuf[WriteBufSz];
	char *ReadPeek, *WritePeek, *ReadEnd;
	FILE *inf, *ouf;
	inline void Open(FILE *i, FILE *o) {
		inf = i, ouf = o, WritePeek = WriteBuf;
		ReadPeek = ReadEnd = ReadBuf;
	}
	inline void Open(const char *i, const char *o) {
		inf = fopen(i, "r"), ouf = fopen(o, "w");
		ReadPeek = ReadEnd = ReadBuf, WritePeek = WriteBuf;
	}
	inline void Flush() {
		fwrite(WriteBuf, 1, WritePeek - WriteBuf, ouf);
		WritePeek = WriteBuf, fflush(ouf);
	}
	inline void Close() {
		if (inf) fclose(inf);
		if (ouf) Flush(), fclose(ouf);
	}
	struct __IOGuard { ~__IOGuard() {Close();} } __IOG;
	inline char GetChar() {
		if (ReadPeek == ReadEnd)
			ReadEnd = ReadBuf + fread(ReadPeek = ReadBuf, 
					1, ReadBufSz, inf);
		return ReadPeek == ReadEnd ? EOF : *(ReadPeek++);
	}
	inline void PutChar(char ch) {
		if (WritePeek == WriteBuf + WriteBufSz) Flush();
		*(WritePeek++) = ch;
	}
	inline char ReadChar() {
		char ch = GetChar();
		while (ch == '\r' || ch == '\n' || ch == '\t' || 
				ch == '\v' || ch == ' ')
			ch = GetChar();
		return ch;
	}
	template <typename T>
	inline T ReadInt() {
		char ch = GetChar();
		bool sgn;
		T x = 0;
		do {
			sgn = false;
			while((ch < '0' || '9' < ch) && ch != '-')
				ch = GetChar();
			if (ch == '-') sgn = true, ch = GetChar();
		} while(ch < '0' || '9' < ch);
		while ('0' <= ch && ch <= '9')
			x = (x << 3) + (x << 1) + (ch ^ 48), ch = GetChar();
		return sgn ? -x : x;
	}
	template<typename T>
	inline void WriteInt(T x) {
		if (x < 0) PutChar('-'), x = -x;
		if (x > 9) WriteInt(x / 10);
		PutChar(x % 10 + 48);
	}
}  // namespace FIO
struct Solver {
	static constexpr int mod = 1e9 + 7;
	std::pair<int, int> lim[100010];
	inline int Qpow(int a, int b, int mod) {
		int res = 1;
		while (b) {
			if (b & 1)
				res = 1LL * res * a % mod;
			a = 1LL * a * a % mod;
			b >>= 1;
		}
		return res;
	}
	inline void Work() {
		int n = FIO::ReadInt<int>();
		int m = FIO::ReadInt<int>();
		int v = FIO::ReadInt<int>();
		for (int i = 1; i <= m; i++) {
			lim[i].first = FIO::ReadInt<int>();
			lim[i].second = FIO::ReadInt<int>();
		}
		std::sort(lim + 1, lim + m + 1);
		int ans = Qpow(v, lim[1].first * 2 - 2, mod);
		ans = 1LL * ans * Qpow(v, (n - lim[m].first) * 2, mod) % mod;
		for (int i = 2; i <= m; i++) {
			if (lim[i].first == lim[i - 1].first && 
					lim[i].second != lim[i - 1].second) {
				FIO::PutChar('0'), FIO::PutChar('\n');
				return;
			} else if (lim[i].first != lim[i - 1].first) {
				int d = lim[i].first - lim[i - 1].first;
				ans = 1LL * ans * (Qpow(v, d * 2, mod) - 
					1LL * (v - 1) * Qpow(v, d - 1, mod) %
				       	mod + mod) % mod;
			}
		}
		FIO::WriteInt(ans), FIO::PutChar('\n');
	}
} S;
int main() {
#ifdef DBG
	FIO::Open(stdin, stdout);
#else
	FIO::Open(PROB ".in", PROB ".out");
#endif
	int T = FIO::ReadInt<int>();
	while (T--) {
		memset(&S, 0, sizeof(S));
		S.Work();
	}
	return 0;
}