use std::collections::{BinaryHeap, VecDeque, HashSet};


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])
        })
        .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(|&(v, _)| v);
    let mut used_vals = VecDeque::new();
    let mut used_area = vec![false; 200001];
    let mut result = 0usize;
    let mut score = 0usize;
    for i in 1..=n {
        while pairs.len() > 0 && used_area[pairs.last().unwrap().1] {
            used_vals.push_back(pairs.pop().unwrap().0);
        }
        if pairs.len() > 0 {
            let &(val, kind) = pairs.last().unwrap();
            if used_vals.len() > 0 && *used_vals.front().unwrap() > x + val {
                score += used_vals.pop_front().unwrap();
            } else {
                pairs.pop().unwrap();
                score += x + val;
                used_area[kind] = true;
            }
        } else {
            score += used_vals.pop_front().unwrap();
        }

        result += score * ccnts[i];
    }
    println!("{}", result);
}