// yukicoder: No.801 エレベーター
// 2019.7.17 bal4u

#include <stdio.h>
#include <string.h>

#if 1
#define gc() getchar_unlocked()
#else
#define gc() getchar()
#endif
int in() {   // 非負整数の入力
	int n = 0, c = gc();
	do n = 10 * n + (c & 0xf); while ((c = gc()) >= '0');
	return n;
}

typedef long long ll;
#define MOD 1000000007
int L[3003], R[3003];
ll dp[2][3003], *cur, *nxt, *t;

int main()
{
	int i, j, N, M, K, N1, ans;
	
	N = in(), M = in(), K = in(), N1 = N+1;
	for (i = 0; i < M; i++) L[i] = in(), R[i] = in();

	dp[0][1] = 1, cur = dp[0], nxt = dp[1];
	for (i = 0; i < K; i++) {
		for (j = 1; j <= N1; j++) cur[j] += cur[j-1];

		for (j = 0; j < M; j++) {
			ll t = cur[R[j]] - cur[L[j]-1];
			nxt[L[j]] += t, nxt[R[j]+1] -= t;
		}
	
		for (j = 1; j <= N1; j++) nxt[j] = (nxt[j] + nxt[j-1]) % MOD;
		t = cur, cur = nxt, nxt = t;
		memset(nxt, 0, sizeof(dp[0]));
    }
	ans = cur[N]; if (ans < 0) ans += MOD;
	printf("%d\n", ans);
	return 0;
}