PROG-T1029: Magnet

#include <iostream>
#include <set>
using namespace std;

int main(){

    int nm, ns, T;
    scanf("%d", &nm);
    scanf("%d", &ns);
    scanf("%d", &T);

    set<int> magnet;
    for(int i = 1; i <= ns; ++i){
        int s, d;
        scanf("%d", &s);
        scanf("%d", &d);
        if(magnet.find(s) == magnet.end()){
            magnet.insert(s);
        } else {
            magnet.erase(s);
        }
        if(magnet.find(s + d) == magnet.end()){
            magnet.insert(s + d);
        } else {
            magnet.erase(s + d);
        }
    }

    if(magnet.find(1) == magnet.end()){
        magnet.insert(1);
    }
    magnet.insert(nm + 1);
    for(int i = 1; i <= T; ++i){
        int x;
        scanf("%d", &x);
        cout << *(magnet.upper_bound(x)) - *(prev(magnet.upper_bound(x))) << "\n";
    }

    return 0;
}