#pragma GCC optimize(3)
#pragma GCC target("avx")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("inline")
#pragma GCC optimize("-fgcse")
#pragma GCC optimize("-fgcse-lm")
#pragma GCC optimize("-fipa-sra")
#pragma GCC optimize("-ftree-pre")
#pragma GCC optimize("-ftree-vrp")
#pragma GCC optimize("-fpeephole2")
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-fsched-spec")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-falign-jumps")
#pragma GCC optimize("-falign-loops")
#pragma GCC optimize("-falign-labels")
#pragma GCC optimize("-fdevirtualize")
#pragma GCC optimize("-fcaller-saves")
#pragma GCC optimize("-fcrossjumping")
#pragma GCC optimize("-fthread-jumps")
#pragma GCC optimize("-funroll-loops")
#pragma GCC optimize("-fwhole-program")
#pragma GCC optimize("-freorder-blocks")
#pragma GCC optimize("-fschedule-insns")
#pragma GCC optimize("inline-functions")
#pragma GCC optimize("-ftree-tail-merge")
#pragma GCC optimize("-fschedule-insns2")
#pragma GCC optimize("-fstrict-aliasing")
#pragma GCC optimize("-fstrict-overflow")
#pragma GCC optimize("-falign-functions")
#pragma GCC optimize("-fcse-skip-blocks")
#pragma GCC optimize("-fcse-follow-jumps")
#pragma GCC optimize("-fsched-interblock")
#pragma GCC optimize("-fpartial-inlining")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("-freorder-functions")
#pragma GCC optimize("-findirect-inlining")
#pragma GCC optimize("-fhoist-adjacent-loads")
#pragma GCC optimize("-frerun-cse-after-loop")
#pragma GCC optimize("inline-small-functions")
#pragma GCC optimize("-finline-small-functions")
#pragma GCC optimize("-ftree-switch-conversion")
#pragma GCC optimize("-foptimize-sibling-calls")
#pragma GCC optimize("-fexpensive-optimizations")
#pragma GCC optimize("-funsafe-loop-optimizations")
#pragma GCC optimize("inline-functions-called-once")
#pragma GCC optimize("-fdelete-null-pointer-checks")
#pragma GCC optimize(2)

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
#define pii pair<int, int>
void solve();

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int T = 1;
//    cin >> T;
    while (T--)solve();
    return 0;
}
void solve(){
    int n;
    cin>>n;
    vector<pii>a(n+1);
    for(int i=1;i<=n;i++){
        cin>>a[i].first>>a[i].second;
    }
    sort(a.begin()+1,a.end());
    int ans=-1e10;
    vector<int>num(n+1),w(n+1);
    for(int i=1;i<=n;i++){
        cin>>w[i];
    }
    priority_queue<int,vector<int>,greater<int>>q;
    auto dfs=[&](auto dfs,int re,int x)->void{
        if(x==0){
            if(re)return;
            while(q.size())q.pop();
            int tmp=0,ok=1,l=1;
            for(int i=1;i<=n;i++){
                if(ok==0)break;
//                cout<<num[i]<<' ';
                tmp+=num[i]*w[i];
                while(l<=n&&a[l].first<=i){
                    q.push(a[l].second);
                    l++;
                }
                for(int j=0;j<num[i]*i;j++) {
                    if(q.size()&&q.top()>=i){
                        q.pop();
                    }
                    else {
                        ok=0;
                        break;
                    }
                }
            }
//            cout<<endl;
            if(ok==1)ans=max(ans,tmp);
            return;
        }
        for(int j=0;j<=re;j+=x){
            num[x]=j/x;
            dfs(dfs,re-j,min(x-1,re-j));
            num[x]=0;
        }
    };
    dfs(dfs,n,n);
    cout<<(ans==-1e10 ? "impossible":to_string(ans))<<endl;
}

answer.code:22:39: warning: bad option ‘-fwhole-program’ to pragma ‘optimize’ [-Wpragmas]
   22 | #pragma GCC optimize("-fwhole-program")
      |                                       ^
answer.code:29:41: warning: bad option ‘-fstrict-overflow’ to pragma ‘optimize’ [-Wpragmas]
   29 | #pragma GCC optimize("-fstrict-overflow")
      |                                         ^
answer.code:31:41: warning: bad option ‘-fcse-skip-blocks’ to pragma ‘optimize’ [-Wpragmas]
   31 | #pragma GCC optimize("-fcse-skip-blocks")
      |                                         ^
answer.code:45:51: warning: bad option ‘-funsafe-loop-optimizations’ to pragma ‘optimize’ [-Wpragmas]
   45 | #pragma GCC optimize("-funsafe-loop-optimizations")
      |                                                   ^
answer.code:55:12: warning: bad option ‘-fwhole-program’ to attribute ‘optimize’ [-Wattributes]
   55 | void solve();
      |            ^
answer.code:55:12: warning: bad option ‘-fstrict-overflow’ to attribute ‘optimize’ [-Wattributes]
answer.code:55:12: warning: bad option ‘-fcse-skip-blocks’ to attribute ‘optimize’ [-Wattributes]
answer.code:55:12: warning: bad option ‘-funsafe-loop-optimizations’ to attribute ‘optimize’ [-Wattributes]
answer.code:55:12: warning: bad option ‘-fwhole-program’ to attribute ‘optimize’ [-Wattributes]
answer.code:55:12: warning: bad option ‘-fstrict-overflow’ to attribute ‘optimize’ [-Wattributes]
answer.code:55:12: warning: bad option ‘-fcse-skip-blocks’ to attribute ‘optimize’ [-Wattributes]
answer.code:55:12: warning: bad option ‘-funsafe-loop-optimizations’ to attribute ‘optimize’ [-Wattributes]
answer.code:57:13: warning: bad option ‘-fwhole-program’ to attribute ‘optimize’ [-Wattributes]
   57 | signed main()
      |             ^
answer.code:57:13: warning: bad option ‘-fstrict-overflow’ to attribute ‘optimize’ [-Wattributes]
answer.code:57:13: warning: bad option ‘-fcse-skip-blocks’ to attribute ‘optimize’ [-Wattributes]
answer.code:57:13: warning: bad option ‘-funsafe-loop-optimizations’ to attribute ‘optimize’ [-Wattributes]
answer.code:67:12: warning: bad option ‘-fwhole-program’ to attribute ‘optimize’ [-Wattributes]
   67 | void solve(){
      |            ^
answer.code:67:12: warning: bad option ‘-fstrict-overflow’ to attribute ‘optimize’ [-Wattributes]
answer.code:67:12: warning: bad option ‘-fcse-skip-blocks’ to attribute ‘optimize’ [-Wattributes]
answer.code:67:12: warning: bad option ‘-funsafe-loop-optimizations’ to attribute ‘optimize’ [-Wattributes]
answer.code: In function ‘void solve()’:
answer.code:81:42: warning: bad option ‘-fwhole-program’ to attribute ‘optimize’ [-Wattributes]
   81 |     auto dfs=[&](auto dfs,int re,int x)->void{
      |                                          ^~~~
answer.code:81:42: warning: bad option ‘-fstrict-overflow’ to attribute ‘optimize’ [-Wattributes]
answer.code:81:42: warning: bad option ‘-fcse-skip-blocks’ to attribute ‘optimize’ [-Wattributes]
answer.code:81:42: warning: bad option ‘-funsafe-loop-optimizations’ to attribute ‘optimize’ [-Wattributes]
In file included from /usr/include/c++/13/string:43,
                 from /usr/include/c++/13/bitset:52,
                 from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:52,
                 from answer.code:50:
/usr/include/c++/13/bits/allocator.h: In destructor ‘constexpr std::__cxx11::basic_string<char>::_Alloc_hider::~_Alloc_hider()’:
/usr/include/c++/13/bits/allocator.h:184:7: error: inlining failed in call to ‘always_inline’ ‘constexpr std::allocator< <template-parameter-1-1> >::~allocator() noexcept [with _Tp = char]’: target specific option mismatch
  184 |       ~allocator() _GLIBCXX_NOTHROW { }
      |       ^
In file included from /usr/include/c++/13/string:54:
/usr/include/c++/13/bits/basic_string.h:181:14: note: called from here
  181 |       struct _Alloc_hider : allocator_type // TODO check __is_final
      |              ^~~~~~~~~~~~