import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int r = sc.nextInt();
        int y = sc.nextInt();
        int g = sc.nextInt();
        int n = sc.nextInt();
        int res = 0;

        while(n-- != 0){
            int k = sc.nextInt();
            int t = sc.nextInt();
            switch (k){
                case 0: res += t;break; //直接通行
                case 1: res += t; break;//红灯等待t秒
                case 2: res += t + r; break;//黄灯等待t秒后是红灯，还得等r秒
                case 3: break;//绿灯，不用等，即不耗时间
            }
        }
        System.out.println(res);
    } 
}