use std::cmp::Reverse;


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

    let mut ccnts = vec![0usize; n+1];
    for &v in c.iter() { ccnts[v] += 1; }
    pairs.sort_by_key(|&(q, _)| Reverse(q));
    let mut used = vec![false; m];
    let mut scores = Vec::with_capacity(n);
    for i in 0..n {
        let (q, k) = pairs[i];
        scores.push(if !used[k] { q+x } else { q });
        used[k] = true;
    }
    scores.sort();
    scores.reverse();
    let mut result = 0usize;
    let mut val = 0usize;
    for i in 0..n {
        val += scores[i];
        result += val * ccnts[i+1];
    }
    println!("{}", result);
}