#include <iostream>

#include <bits/stdc++.h>

#include <string>

using namespace std;

int r,y,g;

void change(long long int sum,int &k,int &t)//最开始显示为t秒，sum秒后为什么状态，此时为k灯

{

    sum%=(r+y+g);///不加此句会超时

    if(k==0)

        return;

    if(sum-t<0)

    {

        t-=sum;

        return;

    }

    else

    {

        sum-=t;

        if(k==1)

            k=3;

        else if(k==3)

            k=2;

        else if(k==2)

            k=1;

    }

    while(sum>=0)//1--》3--》2

    {

        switch (k)

        {

        case 1:

            if(sum-r<0)

            {

                t=r-sum;

                return;

            }

            else

            {

                if(k==1)

                    k=3;

                else if(k==3)

                    k=2;

                else if(k==2)

                    k=1;

                sum-=r;

            }

            break;

        case 2:

            if(sum-y<0)

            {

                t=y-sum;

                return;

            }

            else

            {

                if(k==1)

                    k=3;

                else if(k==3)

                    k=2;

                else if(k==2)

                    k=1;

                sum-=y;

            }

            break;

        case 3:

            if(sum-g<0)

            {

                t=g-sum;

                return;

            }

            else

            {

                if(k==1)

                    k=3;

                else if(k==3)

                    k=2;

                else if(k==2)

                    k=1;

                sum-=g;

            }

            break;

        }

    }

}

int main()

{

    cin>>r>>y>>g;

    int n;

    cin>>n;

    long long int sum=0;

    while(n--)

    {

        int k,t;

        cin>>k>>t;

        change(sum,k,t);

        switch (k)

        {

        case 0:

            sum+=t;

            break;

        case 1:

            sum+=t;

            break;

        case 2:

            sum+=(t+r);

            break;

        case 3:

            break;

        }

    }

    cout<<sum<<endl;

}