#pragma GCC optimize(3)
#pragma GCC optimize(2)
#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
using namespace std;
const int N=5e5+10;
typedef long long ll;
typedef pair<ll,ll> PII;
ll n,m,k;
ll a[N],b[N];
PII e[N];
int cnt=0;
ll ans=-1e18;
ll w[N];
vector<PII> v;
// int cnt[N];

void dfs(int x,int sum,ll val){
    // cout<<x<<" "<<sum<<" "<<val<<endl;
	if(x==0){
		// cnt++;
        vector<int> vv;
        for(int i=v.size()-1;i>=0;i--){
            for(int j=1;j<=v[i].second;j++){
                vv.push_back(v[i].first);
            }
        }
        // sort(vv.begin(),vv.end());
        priority_queue<int,vector<int>,greater<int>> q;
        int j=1;
        for(int i=0;i<vv.size();i++){
            // cout<<vv[i]<<" ";
            while(j<=n&&e[j].first<=vv[i]){
                q.push(e[j].second);
                j++;
            }
            while(q.size()&&q.top()<vv[i]) q.pop();
            int k=1;
            while(k<=vv[i]){
                if(!q.size()){
                    // cout<<endl;
                    return;
                } 
                q.pop();
                k++;
            }
        }
        // cout<<endl;
        // cout<<val<<endl;
        ans=max(ans,val);
	}else{
        if(x==1){
            v.push_back({1,n-sum});
            dfs(x-1,n,val+(n-sum)*w[1]);
            v.pop_back();
            return;
        }
		for(int i=0;i<=n;i++){
			if(sum+i*x>n) break;
            if(i!=0)
            v.push_back({x,i});
			dfs(x-1,sum+i*x,val+w[x]*i);
            if(i!=0)
            v.pop_back();
        }
	}
}


int main(){
	cin>>n;
    for(int i=1;i<=n;i++){
        cin>>e[i].first>>e[i].second;
    }
    for(int i=1;i<=n;i++) cin>>w[i];
    sort(e+1,e+1+n);
	dfs(n,0,0);
    if(ans<-1e13) puts("impossible");
    else
    cout<<ans<<endl;
}