#include <bits/stdc++.h>
char buf[5000000], *p1, *p2;
#define nc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,5000000,stdin),p1==p2)?EOF:*p1++)
template<typename T>
void read_s(T& x) {x=0;int ch;int f=0;while(!isdigit(ch=nc())){ch=='-'&&(f=1);};do{x=x*10+(ch^48);}while(isdigit(ch=nc()));f&&(x=-x);}
template<typename ...Args>
void read(Args& ...args) {
  (read_s(args), ...);
}
#define M 100010
using ll = long long;
#define mod 1000000007ll
ll qp(ll x, ll y) {
  ll ans = 1;
  while (y) {
    if (y & 1) ans = ans * x % mod;
    y >>= 1;
    x = x * x % mod;
  }
  return ans;
}
int n, m;
ll v;
using pii = std::pair<int, int>;
pii a[M];
void gun() {
  read(n, m, v);
  for (int i = 1; i <= m; ++i) {
    read(a[i].first, a[i].second);
  }
  std::sort(a + 1, a + m + 1);
  m = std::unique(a + 1, a + m + 1) - a - 1;
  for (int i = 1; i < m; ++i) {
    if (a[i].first == a[i + 1].first) {
      std::cout << 0 << '\n';
      return;
    }
  }
  ll x = v * v % mod;
  ll ans = 1;
  ans = qp(x, a[1].first - 1) % mod;
  for (int i = 2; i <= m; ++i) {
    ans = ans * (qp(x, a[i].first - a[i - 1].first) - qp(v, a[i].first - a[i - 1].first - 1) * (v - 1) % mod + mod) % mod;
  }
  ans = ans * qp(x, n - a[m].first) % mod;
  std::cout << ans << '\n';
}
int main() {
  freopen("assign.in", "r", stdin);
  freopen("assign.out", "w", stdout);
  std::cin.tie(nullptr) -> sync_with_stdio(false);
  int T;
  read(T);
  while (T--) gun();
  return 0;
}