func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long limit = 1e5 + 1;   long long res = 0, ans = 1e17, sum = 0;   long long a[limit], cost[limit];   long long n;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     cin >> n;     for (long long i = 1; i <= n; i++) cin >> a[i] >> cost[i];     for (long long i = 1; i <= n; i++) {       ans = min(cost[i], ans);       cost[i] = ans;     }     for (long long i = 1; i <= n; i++) res += a[i] * cost[i];     cout << res;   }   