const MOD: usize = 1e9 as usize + 7;

fn main() {
    let mut nmk = String::new();
    std::io::stdin().read_line(&mut nmk).ok();
    let nmk: Vec<usize> = nmk.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nmk[0];
    let m = nmk[1];
    let k = nmk[2];
    let items = (0..m).map(|_| {
            let mut temp = String::new();
            std::io::stdin().read_line(&mut temp).ok();
            let temp: Vec<usize> = temp.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
            (temp[0]-1, temp[1]-1)
        })
        .collect::<Vec<_>>();

    let mut dp = vec![0usize; n];
    dp[0] = 1;
    for _ in 0..k {
        let mut prev_sum = vec![0usize; n+1];
        for i in 0..n {
            prev_sum[i+1] = prev_sum[i] + dp[i];
            prev_sum[i+1] %= MOD;
        }
        let mut next_sum = vec![0usize; n+1];
        for &(l, r) in items.iter() {
            let total = MOD + prev_sum[r+1] - prev_sum[l];
            let total = total % MOD;
            next_sum[l] += total;
            next_sum[l] %= MOD;
            next_sum[r+1] += MOD - total;
            next_sum[r+1] %= MOD;
        }
        for i in 0..n {
            next_sum[i+1] += next_sum[i];
            next_sum[i+1] %= MOD;
        }
        next_sum.pop();
        dp = next_sum;
    }
    println!("{}", dp[n-1]);
}