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

#include <stdio.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;
}

#define MOD 1000000007
int L[3003], R[3003];
int dp[3003][3003];

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

		for (j = 0; j < M; j++) if (dp[i][L[j]]) {
			t = (dp[i][R[j]] - dp[i][L[j]-1]) % MOD;
			dp[i+1][L[j]]   = (dp[i+1][L[j]]   + t) % MOD;
			dp[i+1][R[j]+1] = (dp[i+1][R[j]+1] - t) % MOD;
		}

		for (j = 1; j <= N1; j++) dp[i+1][j] = (dp[i+1][j] + dp[i+1][j-1]) % MOD;
    }
	if (dp[K][N] < 0) dp[K][N] += MOD;
	printf("%d\n", dp[K][N]);
	return 0;
}