/*
    Author : Sparkle_ZH & Sparklee
    Right Output ! & Accepted !
*/

#include <bits/stdc++.h>
#define ull unsigned long long
#define pii pair<int, int>
#define int long long
#define pb push_back
#define fir first
#define sec second
using namespace std;

namespace fast_IO {
    template<typename T> inline void rd(T &x, bool g = 0) {
        x = 0; bool f = 0; char ch = getchar();
        while (! isdigit(ch)) f |= (ch == '-'), ch = getchar();
        while (isdigit(ch)) {
            x = (x << 3) + (x << 1) + ch - '0';
            if (g) break; ch = getchar();
        }
        if (f) x = -x;
    }

    template<typename T, typename... Args> inline void rd(T &first, Args& ... args) {
        rd(first);
        rd(args...);
    }

    template<typename T> inline void write(T x, int f = -1) {
        if (x < 0) putchar('-'), x = -x; static short Stack[50], top(0);
        do Stack[++ top] = x % 10, x /= 10; while (x);
        while (top) putchar(Stack[top --] | 48);
        if (~ f) (f ? putchar('\n') : putchar(' '));
    }
} using namespace fast_IO;

const int L = 1e5 + 5, P = 1e9 + 7;
int n, m, v;
pii a[L];

int qpow(int base, int power) {
    int res = 1; while (power) {
        if (power & 1) res = res * base % P;
        base = base * base % P; power >>= 1;
    } return res;
}

int calc(int t) {
    if (! t) return 1;
    int tot = qpow(v, 2 * t), ext = qpow(v, t - 1) * (v - 1) % P;
    return (tot + P - ext) % P;
}

void solve() {
    rd(n, m, v);
    for (int i = 1; i <= m; i ++)
        rd(a[i].fir, a[i].sec);

    sort(a + 1, a + 1 + m);
    int ans = qpow(v, 2 * (a[1].fir - 1)) * qpow(v, 2 * (n - a[m].fir)) % P;

    for (int i = 2; i <= m; i ++) {
        if (a[i].fir == a[i - 1].fir && a[i].sec != a[i - 1].sec) {
            puts("0"); return ;
        } ans = ans * calc(a[i].fir - a[i - 1].fir) % P;
    }

    write(ans, 1);
}

signed main() {
    freopen("assign.in", "r", stdin);
    freopen("assign.out", "w", stdout);

    int t; rd(t);
    while (t --) solve();

    return 0;
}