#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<algorithm>

using namespace std;

#define int long long
#define rep(i,n) for(int i = 0; i < (n); i++)
#define INF ((long long)1e18)
#define MOD ((int)1e9+7)
#define endl "\n"

#define yn(f) ((f)?"Yes":"No")
#define YN(f) ((f)?"YES":"NO")

#define MAX 3100

int N, M, K;
int _floor[MAX][MAX];
int L[MAX], R[MAX];

signed main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	cout<<fixed<<setprecision(10);
	
	cin>>N>>M>>K;
	
	for(int i = 0; i < M; i++){
		cin>>L[i]>>R[i];
	}
	
	_floor[0][1] = 1;
	for(int i = 1; i <= K; i++){
		for(int j = 0; j <= N; j++){
			if(j)_floor[i-1][j] += _floor[i-1][j-1];
			_floor[i-1][j] %= MOD;
		}
		for(int j = 0; j < M; j++){
			int sum = (MOD + _floor[i-1][R[j]] - _floor[i-1][L[j]-1])%MOD;
			_floor[i][R[j]+1] = (MOD+_floor[i][R[j]+1]-sum)%MOD;
			_floor[i][L[j]]   = (MOD+_floor[i][L[j]]+sum)%MOD;
		}
		for(int j = 0; j <= N; j++){
			if(j)_floor[i][j] += _floor[i][j-1];
			_floor[i][j] %= MOD;
		}
	}
	
	cout<<_floor[K][N]<<endl;
	
	return 0;
}