#include <bits/stdc++.h>
using namespace std;
#define INF 1000000000
#define MOD 1000000007
using ll=long long;
using Graph=vector<vector<int>>;

int main(){
  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];
    L[i]--;
  }

  vector<vector<ll>> dp(K+1,vector<ll>(N,0));
  dp[0][0]=1;
  for(int i=0;i<K;i++){
    vector<ll> sum(N+1,0);
    for(int j=0;j<N;j++){
      sum[j+1]=sum[j]+dp[i][j];
    }
    vector<ll> diff(N+1,0);
    for(int j=0;j<M;j++){
      ll x=sum[R[j]]-sum[L[j]];
      x%=MOD;
      diff[L[j]]+=x;
      diff[R[j]]-=x;
    }
    dp[i+1][0]=diff[0];
    for(int j=1;j<N;j++){
      dp[i+1][j]=dp[i+1][j-1]+diff[j];
    }
    for(int j=0;j<N;j++){
      dp[i+1][j]%=MOD;
    }
  }
  cout<<dp[K][N-1]<<endl;

}