#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <utility>
using ll = long long;
#define MOD 1000000007
using namespace std;

int main(){
    int N, M, K;
    cin >> N >> M >> K;
    vector<int> L(M), R(M);
    vector<vector<int>> dp(K+1,vector<int>(N+1,0));
    dp[0][1] = 1;
    for(int i = 0; i < M; i++)
    {
        cin >> L[i] >> R[i];
    }
    for(int count = 0; count < K; count++)
    {
        for(int height = 1; height < N+1; height++)
        {
            for(int i = 0; i < M; i++)
            {
                if (L[i] <= height && R[i] >= height) {
                    for(int j = L[i]; j <= R[i]; j++)
                    {
                        dp[count + 1][j] += dp[count][height] % MOD;
                        dp[count + 1][j] %= MOD;
                    }
                }
            }
        }
    }
    cout << dp[K][N] << endl;
    return 0;
}