#include <bits/stdc++.h>
std::map<std::string,int>id;
typedef long long ll;
const int N=1e6+10;
std::vector<int>v[N];
int a[N];
char buf[N];
int main(){
    int n,k;
    scanf("%d%d",&n,&k);
    for(int i=1;i<=n;i++){
        scanf(" %s%d",buf,a+i);
        id[buf]=i;
    }
    int m;
    scanf("%d",&m);
    for(int i=1;i<=m;i++){
        int x;
        scanf(" %s%d",buf,&x);
        v[id[buf]].push_back(x);
    }
    ll ans=0;
    int mxsize=0;
    std::priority_queue<ll>heap;
    for(int i=1;i<=n;i++)if(!v[i].empty()){
        int mx=*std::max_element(v[i].begin(),v[i].end());
        int ct=0;
        if(a[i]<mx){
            k-=mx-a[i];
            a[i]=mx;
        }
        for(int x:v[i])
            if(x<a[i])
                ans+=a[i];
            else
                ct++;
        heap.push(1ll*ct*a[i]+v[i].size());
        mxsize=std::max(mxsize,(int)v[i].size());
    }
    if(k<0){
        puts("-1");
        return 0;
    }
    while(k&&!heap.empty()&&heap.top()>mxsize){
        ans+=heap.top();
        heap.pop();
        k--;
    }
    ans+=1ll*mxsize*k;
    printf("%lld\n",ans);
}