#include <bits/stdc++.h>
using namespace std;
void RD(int &x) { scanf("%d", &x); }
void RD(long long &x) { scanf("%I64d", &x); }
void RD(unsigned int &x) { scanf("%u", &x); }
void RD(double &x) { scanf("%lf", &x); }
void RD(int &x, int &y) { scanf("%d%d", &x, &y); }
void RD(long long &x, long long &y) { scanf("%I64d%I64d", &x, &y); }
void RD(unsigned int &x, unsigned int &y) { scanf("%u%u", &x, &y); }
void RD(double &x, double &y) { scanf("%lf%lf", &x, &y); }
void RD(int &x, int &y, int &z) { scanf("%d%d%d", &x, &y, &z); }
void RD(long long &x, long long &y, long long &z) {
  scanf("%I64d%I64d%I64d", &x, &y, &z);
}
void RD(unsigned int &x, unsigned int &y, unsigned int &z) {
  scanf("%u%u%u", &x, &y, &z);
}
void RD(double &x, double &y, double &z) { scanf("%lf%lf%lf", &x, &y, &z); }
void RD(char &x) { x = getchar(); }
void RD(char *s) { scanf("%s", s); }
void RD(string &s) { cin >> s; }
void PR(int x) { printf("%d\n", x); }
void PR(int x, int y) { printf("%d %d\n", x, y); }
void PR(long long x) { printf("%I64d\n", x); }
void PR(unsigned int x) { printf("%u\n", x); }
void PR(unsigned long long x) { printf("%I64u\n", x); }
void PR(double x) { printf("%.6lf\n", x); }
void PR(char x) { printf("%c\n", x); }
void PR(char *x) { printf("%s\n", x); }
void PR(string x) { cout << x << endl; }
const int mod = 1000000007;
const long long inf = ((long long)1) << 60;
const int INF = 100000000;
const int N = 1000005;
vector<pair<int, int> > V;
long long Pow[N];
int n, m, K;
void init() {
  Pow[0] = 1;
  int i;
  for (i = 1; i <= N - 1; i++) Pow[i] = Pow[i - 1] * 2 % mod;
}
int main() {
  init();
  while (scanf("%d", &n) != -1) {
    RD(m, K);
    V.clear();
    int i, x, y, cnt, flag = 1;
    for (i = 1; i <= m; i++) {
      RD(x, y);
      if (y - x != 1 && y - x != K + 1) flag = 0;
      if (y - x == K + 1) V.push_back(make_pair(x, y));
    }
    if (!flag) {
      puts("0");
      continue;
    }
    sort(V.begin(), V.end());
    if (!K || K >= n - 1) {
      puts("1");
      continue;
    }
    for (i = 0; i < V.size(); i++)
      if (!(V[i].first >= V[0].first && V[i].first < V[0].second)) {
        break;
      }
    if (i < V.size()) {
      puts("0");
      continue;
    }
    long long ans = 0;
    if (!V.size()) ans++;
    int t = V.size();
    for (i = 1; i <= n; i++) {
      x = i;
      y = i + K + 1;
      cnt = t;
      if (y > n || t && x > V[0].first) break;
      if (t && !(x <= V[0].first && V[t - 1].first < y)) continue;
      if (t && x == V[0].first) cnt--;
      y = ((y) < (n - K) ? (y) : (n - K));
      ans += Pow[y - x - 1 - cnt];
      ans %= mod;
    }
    PR(ans);
  }
  return 0;
}
