ccf201812-1小明上学

r,y,g = list(map(int,input().split()))
n = int(input())
time =0
for i in range(n):
    k,t = list(map(int,input().split()))
    if(k == 0):  #无灯
        time += t
    elif(k == 1):  #红灯
        time += t
    elif(k == 2):  #黄灯
        time += (t + r)
    elif(k == 3):  #绿灯
        time += 0
print(time)