#include <bits/stdc++.h>
using namespace std;
using i64 = long long;
#define rep(i,s,e) for(int (i) = (s);(i) <= (e);(i)++)
#define all(x) x.begin(),x.end()

const i64 MOD = 1e9 + 7;

int main() {
  i64 N,M,K;
  cin >> N >> M >> K;
  vector<pair<i64,i64>> vec(M);
  for(auto& v : vec) {
    cin >> v.first >> v.second;
  }
  vector<i64> dp(N + 2,0);
  vector<i64> sum(N + 2, 0);
  dp[1] = 1;

  for(int c = 0;c < K;c++) {
    rep(i,1,N) sum[i] = (sum[i - 1] + dp[i]) % MOD;
    rep(i,1,N) dp[i] = 0;
    for(const auto& v : vec) {
      i64 a = v.first;
      i64 b = v.second;
      dp[a] = (dp[a] + (sum[b] - sum[a - 1] + MOD) % MOD) % MOD;
      dp[b + 1] = (dp[b + 1] - (sum[b] - sum[a - 1] + MOD) % MOD + MOD) % MOD;
    }
    rep(i,1,N) dp[i] = (dp[i] + dp[i - 1]) % MOD;
  }
  cout << dp[N] << endl;
}