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

#define int long long

#define MOD 1000000007
int dp[3010][3010];

signed main(){
    int n, m, k;
    int l[3010], r[3010];

    cin >> n >> m >> k;
    for(int i = 0;i < m;i++){
        cin >> l[i] >> r[i];
    }

    dp[0][1] = 1;

    for(int i = 1;i <= k;i++){
        int ta[3010] = {};
        for(int j = 1;j <= n;j++){
            dp[i-1][j] = (dp[i-1][j] + dp[i-1][j-1]) % MOD;
        }

        for(int j = 0;j < m;j++){
            int tmp = (MOD+dp[i-1][r[j]] - dp[i-1][l[j]-1]) % MOD;
            ta[r[j]+1] -= tmp;
            ta[l[j]] += tmp;
        }

        int imos = ta[0];
        for(int j = 1;j <= n;j++){
            imos += ta[j];
            dp[i][j] = imos % MOD;
        }
    }

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