#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
using namespace std;
typedef long long ll;
int INF = (1LL << 30) - 1;
int MOD = 1e9+7;
main(){
    ll N,M,K;
    cin >> N >> M >> K;
    vector<int> L(M),R(M);
    rep(i,0,M){
        cin >> L[i] >> R[i];
        L[i]--,R[i]--;
    }
    ll dp[K+1][N+1] = {};
    dp[0][0] = 1;
    rep(i,0,K){
        vector<ll> accum(N+1);
        rep(j,0,N)accum[j+1] = (accum[j] + dp[i][j]) % MOD;
        rep(j,0,M){
            ll num = (accum[R[j]+1] - accum[L[j]] + MOD) % MOD;
            dp[i+1][L[j]] = (dp[i+1][L[j]] + num) % MOD;
            dp[i+1][R[j]+1] = (dp[i+1][R[j]+1] - num + MOD) % MOD;
        }
        dp[i+1][0] %= MOD;
        rep(j,0,N)dp[i+1][j+1] = (dp[i+1][j+1] + dp[i+1][j]) % MOD;
    }
    //rep(i,0,N)cout << dp[K][i] << " ";cout << endl;
    cout << dp[K][N-1] << endl;
}