#include <iostream>
#include <cstdio>

using namespace std;

typedef pair<int, int> PII;

const int N = 3010, MOD = 1e9 + 7;

PII p[N];
int n, m, k, f[N][N], ps[N][N]; // 坐i次电梯到第j层的方案数

int main() {
    // freopen("lift.in", "r", stdin);
    // freopen("lift.out", "w", stdout);

    scanf("%d%d%d", &n, &m, &k);
    for (int i = 1; i <= m; ++i) scanf("%d%d", &p[i].first, &p[i].second);

    f[0][1] = 1;
    for (int i = 1; i <= n; ++i) ps[0][i] = 1;
    for (int i = 1; i <= k; ++i) {
        for (int j = 1; j <= m; ++j) {
            int x = (0LL + ps[i - 1][p[j].second] - ps[i - 1][p[j].first - 1] + MOD) % MOD;
            (f[i][p[j].first] += x) %= MOD;
            ((f[i][p[j].second + 1] -= x) += MOD) %= MOD;
        }
        ps[i][1] = f[i][1];
        for (int j = 2; j <= n; ++j) {
            (f[i][j] += f[i][j - 1]) %= MOD;
            ps[i][j] = (0LL + ps[i][j - 1] + f[i][j]) % MOD;
        }
    }

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

    return 0;
}