#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
using namespace std;
const int N=1000;
int main()
{
int r,y,g,i,n,x,time,sum=0;
cin>>r>>y>>g>>n;
for(i=0;i<n;i++){
cin>>x;
cin>>time;
if(x==0||x==1){
sum+=time;
}else if(x==2){
time+=r;
sum+=time;
}
}
cout<<sum;
}