#include <bits/stdc++.h>
#define INF 1000000001LL
#define MOD 1000000007LL
#define long long long
#define all(x) x.begin(),x.end()
using namespace std;

long dp[3001][3002];
long hap[3001];
int main()
{
	ios_base::sync_with_stdio(0); 
    cin.tie(0);

	int n,m,k;
	cin >> n >> m >> k;

	vector<pair<int,int>> ev(m);

	for(int i = 0; i<m; i++)
		cin >> ev[i].first >> ev[i].second;

	dp[0][1] = 1;	
	for(int i = 0; i<k; i++)
	{
		for(int j = 1; j<=n; j++)
			hap[j] = (hap[j-1]+dp[i][j])%MOD;
		for(int j= 0; j<m; j++)
		{
			int r = ev[j].second;
			int l = ev[j].first;
			long sum = (hap[r]-hap[l-1]+MOD)%MOD;
			dp[i+1][l]+=sum;
			dp[i+1][r+1]-=sum;
		}

		for(int j = 1; j<=n; j++)
			dp[i+1][j]+=dp[i+1][j-1];
		for(int j = 1; j<=n; j++)
			dp[i+1][j]%=MOD;
	}

	cout << dp[k][n] << endl;

	
    return 0;
}