#include <bits/stdc++.h>
using namespace std;
namespace QYB {
  using ll = long long; const int P = 1000000007;
  int n, m, v; vector<pair<int, int> > vec;
  char getchar() {
    static char buf[1 << 25], *p1 = buf, *p2 = buf;
    return p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1 << 25, stdin)) == buf? EOF: *p1++;
  } int read() {
    int res = 0; char ch = getchar();
    while (ch < 48 || ch > 57) ch = getchar();
    while (ch >= 48 && ch <= 57) res = res * 10 + ch - 48, ch = getchar();
    return res;
  } int power(int a, int b) {
    int res = 1;
    for (; b; a = (ll)a * a % P, b >>= 1) {
      if (b & 1) res = (ll)res * a % P;
    } return res;
  } int main() {
    freopen("assign.in", "r", stdin);
    freopen("assign.out", "w", stdout);
    for (int T = read(); T; T--) {
      n = read(); m = read(); v = read();
      vec.clear();
      for (int i = 1; i <= m; i++) {
        int a = read(), b = read();
        vec.push_back({a, b});
      } sort(vec.begin(), vec.end());
      int ans = 1;
      for (int i = 1; i < vec.size(); i++) {
        if (vec[i].first == vec[i - 1].first) {
          if (vec[i].second == vec[i - 1].second) continue;
          else { ans = 0; break; }
        } int x = vec[i].first - vec[i - 1].first;
        ans = (power(v, 2 * x) - (ll)power(v, x - 1) * (v - 1) % P + P) % P * ans % P;
      } ans = (ll)power(v, 2 * (n - vec.back().first + vec[0].first - 1)) * ans % P;
      printf("%d\n", ans);
    } return 0;
  }
} int main() { return QYB::main(); }