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 lines = (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 psummary = vec![0usize; n+1];
        for i in 0..n {
            psummary[i+1] = psummary[i] + dp[i];
            psummary[i+1] %= MOD;
        }
        let mut next_dp = vec![0usize; n];
        for &(l, r) in lines.iter() {
            let sumval = MOD + psummary[r+1] - psummary[l];
            let sumval = sumval % MOD;
            next_dp[l] += sumval;
            next_dp[l] %= MOD;
            if r+1 < n {
                next_dp[r+1] += MOD - sumval;
                next_dp[r+1] %= MOD;
            }
        }
        for i in 0..n-1 {
            next_dp[i+1] += next_dp[i];
            next_dp[i+1] %= MOD;
        }
        dp = next_dp;
    }
    println!("{}", dp[n-1]);
}