CCF 201812-1 小明上学

#include <iostream>
#include <bits/stdc++.h>
#include <string>

using namespace std;

int main()
{
    int r,y,g;
    cin>>r>>y>>g;
    int n;
    cin>>n;
    int sum=0;
    while(n--)
    {
        int k,t;
        cin>>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;
}