#include <iostream>
#include <cstdio>

using namespace std;

const int N = 3010, MOD = 1000000007;

int f[N][N], sum[N][N], l[N], r[N];

int main() {
    int n, m, k;
    scanf("%d%d%d", &n, &m, &k);
    for (int i = 1; i <= m; ++i) {
        scanf("%d%d", &l[i], &r[i]);
    }

    f[0][1] = 1;
    for (int i = 1; i <= n; ++i) {
        sum[0][i] = 1;
    }

    for (int i = 1; i <= k; ++i) {
        for (int j = 1; j <= m; ++j) {
            int contrib = (sum[i - 1][r[j]] - sum[i - 1][l[j] - 1] + MOD) % MOD;
            (f[i][l[j]] += contrib) %= MOD;
            f[i][r[j] + 1] = (f[i][r[j] + 1] - contrib + MOD) % MOD;
        }
        sum[i][1] = f[i][1];
        for (int j = 2; j <= n; ++j) {
            (f[i][j] += f[i][j - 1]) %= MOD;
            sum[i][j] = (sum[i][j - 1] + f[i][j]) % MOD;
        }
    }

    printf("%d\n", f[k][n]);

    return 0;
}