// MagicDark
#include <bits/stdc++.h>
#define debug cerr << "\33[33m[" << __LINE__ << "]\33[m "
#define all(x) x.begin(), x.end()
#define SZ(x) ((int) x.size() - 1)
#define ms(x, y) memset(x, y, sizeof x)
#define F(i, x, y) for (int i = (x); i <= (y); ++i)
#define DF(i, x, y) for (int i = (x); i >= (y); --i)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
template <typename T> T& chkmin(T& x, T y) {return x = min(x, y);}
template <typename T> T& chkmax(T& x, T y) {return x = max(x, y);}
template <typename T> T& read(T& x) {
    x = 0; int f = 1; char c = getchar();
    for (; !isdigit(c); c = getchar()) if (c == '-') f = - 1;
    for (; isdigit(c); c = getchar()) x = (x << 1) + (x << 3) + (c ^ 48);
    return x *= f;
}
const int N = 1e5 + 10, MOD = 1e9 + 7;
int n, m, v;
//  f[2], nf[2];
pair <int, int> t[N];
int power(int x, int y = MOD - 1) {
    int ans = 1;
    for (; y; x = (ll) x * x % MOD, y >>= 1)
        if (y & 1) ans = (ll) ans * x % MOD;
    return ans;
}
void add(int& x, ll y) {
    x = (x + y) % MOD;
}
void zhk() {
    read(n), read(m), read(v);
    F(i, 1, m) {
        read(t[i].first), read(t[i].second);
    }
    sort(t + 1, t + m + 1);
    // int f[2];
    // ms(f, 0);
    // f[0] = 1;
    // int vv = (ll) v * v % MOD;
    // int w = power(((ll) v * v - 1) % MOD);
    int ans = 1;
    F(i, 1, m) {
        if (t[i].first == t[i - 1].first) {
            if (t[i].second != t[i - 1].second) {
                cout << 0 << '\n';
                return;
            }
            continue;
        }
        if (i == 1) {
            ans = power(v, (t[i].first - 1) * 2);
        } else {
            // ans = (ll) ans * power(vv, t[i].first - 1);
            int len = t[i].first - t[i - 1].first - 1;
            ans = (ll) ans * (power(v, 2 * len + 2) - (ll) (v - 1) * power(v, len) % MOD + MOD) % MOD;
            // add(s, power(v, ));
        }
    }
    ans = (ll) ans * power(v, (n - t[m].first) * 2) % MOD;
    // ans = (ans + MOD)
    cout << ans << '\n';
    // if (t[m].first )
}
signed main() {
    freopen("assign.in", "r", stdin);
    freopen("assign.out", "w", stdout);
    int _; read(_);
    while (_--) zhk();
    return 0;
}
/*
why
*/