int dijkstra(vector<pair<int,int>>g[N],int dist[N],int n,int k){
	dist[s]=0;
	for(int ird=0;rd<n;rd++){
		int cur=-1;
		for(int i=0;i<n;i++){
			if(!vis[i]&&(cur==-1||dist[i]<dist[cur]))cur=i;
		}
		for(auto [dst,weight]:g[car]){
			if(dist[dst]>weight+dist[cur]){
				dist[dst]=weight+dist[cur];
			}
		}
		vis[cur]=1;
	}
}
#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<map>
#include<unordered_map>
#include<queue>
#include<stack>
#define int long long
using namespace std;
int n;
struct Node{
	int t,d;
	bool friend operator <(Node x,Node y){
		double a=1.0*x.d/x.t/2.0,b=1.0*y.d/y.t/2.0;
		return a>b;
	}
}a[100005];
signed main(){
	int ans=0;
	int sum=0;
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>a[i].t>>a[i].d;
		sum+=a[i].d;
	}
	sort(a+1,a+n+1);
	for(int i=1;i<=n;i++){
		sum-=a[i].d;
		ans+=2*a[i].t*sum;
	}
	cout<<ans;
	return 0;
}