#include <bits/stdc++.h>

using namespace std;

int main() {
    int N, M, K;
    
    cin>> N >> M >> K;
    
    vector<int> L(M), R(M);
    vector<vector<int>> dp(3001, vector<int>(3001, -1));
    
    for (int i = 0; i < M; i++)
        cin >> L[i] >> R[i];
        
    dp[K][N] = 1;
    for (int i = 0; i < N; i++)
    	dp[K][i] = 0;
    
    auto solve = [&](auto f, int k, int n) {
        if (dp[k][n] >= 0)
            return dp[k][n];
            
        int r = 0;
        for (int i = 0; i < M; i++)
            if (n >= L[i] && n <= R[i])
                for (int j = L[i]; j <= R[i]; j++)
                    r = (r + f(f, k + 1, j)) % 1000000007;
                    
        dp[k][n] = r;
        return r;
    };
    
    int r = 0;
    
    cout << solve(solve, 0, 1) << endl;
    
    return 0;
}