#include <bits/stdc++.h>
typedef long long ll;
using std::min; using std::max;
#define rd() read<ll>()
#define lowbit(x) (-x & x)
#define E(i, l, r) for (int i = l; i <= r; ++ i)
#define FILE(filename) { \
  freopen(#filename ".in", "r", stdin); \
  freopen(#filename ".out", "w", stdout); \
}
template <typename T> inline T read() {
  T x = 0; bool f = 0; char c = getchar();
  while (c < '0' || c > '9') {if (c == '-') f = 1; c = getchar();}
  while (c >= '0' && c <= '9') x = (x << 3) + (x << 1) + (c ^ 48), c = getchar();
  return f ? -x : x;
}
template <typename T> void write(T x) {
  if (x < 0) putchar('-'), x = -x;
  if (x / 10) write(x / 10); putchar((x % 10) ^ 48);
}
namespace pigeon {
  const int N = 1e5 + 5;
  const int mod = 1e9 + 7;
  int n, m, v;
  std::pair<int, int> a[N];
  int qpow(int x, int y = mod - 2) {
    int res = 1;
    while (y) {
      if (y & 1) res = 1ll * res * x % mod;
      x = 1ll * x * x % mod; y >>= 1;
    } return res;
  }
  void Main() {
    n = rd(); m = rd(); v = rd();
    E(i, 1, m) {
      int x, y;
      x = rd(); y = rd();
      a[i] = std::make_pair(x, y);
    }
    int ans = 1, sum = n - 1;
    std::sort(a + 1, a + m + 1);
    E(i, 1, m - 1)
      if (a[i].first == a[i + 1].first && a[i].second != a[i + 1].second) {
        write(0); puts("");
        return;
      }
    E(i, 1, m - 1) {
      int len = a[i + 1].first - a[i].first;
      sum -= len; if (len == 0) continue;
      int tmp = 1ll * (v - 1) * qpow(v, len - 1) % mod;
      ans = 1ll * ans * (qpow(1ll * v * v % mod, len) - tmp + mod) % mod;
    } write(1ll * ans * qpow(1ll * v * v % mod, sum) % mod); puts("");
  }
}
int main() {
  FILE(assign);
  int T = rd();
  while (T --) pigeon::Main();
  return 0;
}