#include <bits/stdc++.h>

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)
#define unless(p) if(!(p))
#define until(p) while(!(p))

using ll = std::int64_t;
using P = std::tuple<int,int>;

constexpr ll MOD = 1'000'000'007;
int N, M, K;
int L[3100], R[3100];

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    std::cin >> N >> M >> K;

    for(int i=0;i<M;++i){
        std::cin >> L[i] >> R[i];
    }

    std::vector<ll> dp(N + 1, 0);
    dp[1] = 1;

    for(int _=0;_<K;++_){
        for(int i=2;i<=N;++i){
            dp[i] = (dp[i] + dp[i-1]) % MOD;
        }

        std::vector<ll> v(N + 1, 0);

        for(int i=0;i<M;++i){
            ll s = (dp[R[i]] + MOD - dp[L[i]-1]) % MOD;
            v[L[i]] = (v[L[i]] + s) % MOD;
            if(R[i] < N){
                v[R[i]+1] = (v[R[i]+1] + MOD - s) % MOD;
            }
        }

        for(int i=2;i<=N;++i){
            v[i] = (v[i] + v[i-1]) % MOD;
        }

        dp = std::move(v);
    }

    ll c = dp[N];
    std::cout << c << std::endl;
}