#include <bits/stdc++.h>   using namespace std;   const long long MAXN = 1e2 + 7;   long long p[MAXN], dp[MAXN];   pair<long long, long long> fig[MAXN];   int32_t main() {     long long n;     cin >> n;     for (long long i = 0; i < n; ++i) cin >> fig[i].second >> fig[i].first;     sort(fig, fig + n);     long long t;     cin >> t;     for (long long i = 1; i <= t; ++i) cin >> p[i];     p[t + 1] = (1LL << 60);     long long pos = 1, ans = 0, sum = 0;     for (long long i = 0; i < n; ++i) {       while (fig[i].second) {         if (p[pos] - sum > fig[i].second) {           sum += fig[i].second;           ans += fig[i].second * pos * fig[i].first;           fig[i].second = 0;         } else {           ans += fig[i].first * (p[pos] - sum) * pos;           fig[i].second -= p[pos] - sum;           sum = p[pos];           pos++;         }       }     }     cout << ans <<   n ;   }   