#include<bits/stdc++.h>
using namespace std;
#define int long long

const int MOD = 1e9+7;

int dp[3010][3010];
//i回目の移動でj階にいる場合の数

signed main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  int N,M,K; cin >> N >> M >> K;
  vector<int> L(M),R(M);
  for(int i = 0; i < M; i++){
    cin >> L[i] >> R[i];
  }

  dp[0][1] = 1;
  for(int i = 0; i < K; i++){
    vector<int> dp2(N+1,0); //累積和
    for(int j = 1; j <= N; j++){
      dp2[j] += dp2[j-1] + dp[i][j];
      dp2[j] %= MOD;
    }
    for(int j = 0; j < M; j++){
      int sum = dp2[R[j]] - dp2[L[j]-1] + MOD;
      sum %= MOD;
      dp[i+1][L[j]] += sum;
      dp[i+1][L[j]] %= MOD;
      dp[i+1][R[j]+1] -= sum,dp[i+1][R[j]+1] += MOD;
      dp[i+1][R[j]+1] %= MOD;
    }

    for(int j = 1; j <= N; j++){
      dp[i+1][j] += dp[i+1][j-1];
      dp[i+1][j] %= MOD;
    }
  }
  cout << dp[K][N] << endl;

  return 0;
}