#include <iostream>
#include <algorithm>
using namespace std;

inline long long read() {
    long long num = 0, fg = 1;
    char c = getchar();
    while(!isdigit(c)) {
        if (c == '-') fg = -fg;
        c = getchar();
    }
    while(isdigit(c)) {
        num = num * 10 + c - '0';
        c = getchar();
    }
    return num * fg;
}

const long long mod = 1e9 + 7;
long long qpow(long long, long long);
int Solve();
int main() {
    freopen("assign.in", "r", stdin);
    freopen("assign.out", "w", stdout);
    int T = read();
    for (int i = 1; i <= T; i++) Solve();
    return 0;
}

namespace M1 {
int solve();
}

#define MAXM 1500006
long long n, m, v;
struct Task {
    int pos, val;
    bool operator< (const Task tas) const {
        return this->pos < tas.pos;
    }
};
Task a[MAXM];

namespace ACT {
int solve();
}

int Solve() {
    n = read(), m = read(), v = read();
    for (int i = 1; i <= m; i++) a[i].pos = read(), a[i].val = read();

    sort (a + 1, a + m + 1);
    if (m == 1) return M1::solve();
    return ACT::solve();

    return 0;
}

namespace ACT {
int solve() {

    //printf("m = %d, n = %d, v = %d\n", m, n, v);
    for (int i = 2; i <= m; i++) if (a[i].pos == a[i - 1].pos && a[i].val != a[i - 1].val) {
        printf("0\n");
        return 0;
    }

    long long ans = 1ll;

    a[0].pos = 0;

    for (int i = 2; i <= m; i++) {
        if (a[i].pos == a[i - 1].pos) continue;
        long long x = a[i].pos - a[i - 1].pos - 1;
        //printf("x = %lld\n", x);
        ans = ans * (qpow(v * v % mod, x + 1) % mod - (v - 1ll) * qpow(v, x) % mod) % mod;
    }

    ans = (ans % mod + mod) % mod;
    //printf("tmp ans = %lld\n", ans);

    if (a[1].pos != 1) {
        ans = ans * qpow(v * v % mod, a[1].pos - 1) % mod;
    }
    if (a[m].pos != n) {
        ans = ans * qpow(v * v % mod, n - a[m].pos) % mod;
    }
    ans = (ans % mod + mod) % mod;
    printf("%lld\n", ans);
    return 0;
}
}

namespace M1 {
int solve() {

    long long ans = qpow(v * v % mod, n - 1);
    printf("%lld\n", ans % mod);
    return 0;
}
}

long long qpow(long long bas, long long po) {
    long long ret = 1;
    while(po) {
        if (po & 1ll) ret = ret * bas % mod;
        bas = bas * bas % mod;
        po >>= 1ll;
    }
    return ret;
}