// 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];

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

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