#include<iostream>
using namespace std;
int main()
{
    string name,id;
    cin>>name>>id;
    int log,hour[log],task[log];
    cin>>log;
    int chour=0,ctask=0;
    for(int i=0;i<log;i++)
    {
        cin>>hour[i];
        chour+=hour[i];
        while(int j=i)
        {
            cin>>task[j];
            ctask+=task[j];
        }
    }
    cout<<ctask/chour;
    retur
}