#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 dp[3030][3030];

int dfs(int t, int x)
{
    if(t == K){
        if(x == N){
            return 1ll;
        }
        else {
            return 0;
        }
    }
    if(~dp[t][x]){
        return dp[t][x];
    }
    int res = 0;
    for(int i = 0; i < M; i++){
        if(L[i] <= x && x <= R[i]){
            for(int j = L[i]; j <= R[i]; j++){
                res += dfs(t + 1, j);
                res %= mod;
            }
        }
    }
    return dp[t][x] = res;
}

signed main()
{
    cin >> N >> M >> K;
    for(int i = 0; i < M; i++){
        cin >> L[i] >> R[i];
    }
    memset(dp, -1ll, sizeof(dp));
    cout << dfs(0, 1) << endl;




    return 0;
}

/*



*/