#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define int long long
#define mk make_pair
#define pb push_back
#define pf push_front
typedef pair<int, int> pii;
#define INF (1 << 30)
#define INFL (1ll << 60ll);
#define mod 1000000007
#define se second
#define fi first

int N, M, K;
int L[3030], R[3030];
int U[3030], O[3030];
int dp[3030][3030];

signed main()
{
    cin >> N >> M >> K;
    for(int i = 0; i < M; i++){
        cin >> L[i] >> R[i];
    }
    dp[0][1] = 1;
    for(int i = 0; i < K; i++){
        for(int j = 1; j <= N; j++){
            dp[i][j] += dp[i][j - 1];
            dp[i][j] %= mod;
        }
        for(int j = 0; j < M; j++){
            int sum = dp[i][R[j]] - dp[i][L[j] - 1];
            dp[i + 1][L[j]] += sum;
            dp[i + 1][R[j] + 1] -= sum;
        }
        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;
}

/*



*/