#include <iostream>
#include <algorithm>
#include <vector>
#include <set>
#include <cmath>
#include <cstdio>

using namespace std;

typedef long long ll;

struct frilenser
{
	int a;
    	double p;
        };

        static inline bool operator<(const frilenser& a, const frilenser& b) noexcept
        {
        	return a.p < b.p;
            }

            static inline bool operator==(const frilenser& a, const frilenser& b) noexcept
            {
            	return a.p == b.p;
                }

                static set<frilenser> F;
                int main()
                {
                	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
                    	int n;
                        	unsigned long long suma = 0;
                            	cin >> n;
                                	for (int i = 0; i < n; i++)
                                    	{
                                        		frilenser f;
                                                		cin >> f.a >> f.p;
                                                        		f.p /= 100;
                                                                		suma += f.a;
                                                                        		auto fi = F.find(f);
                                                                                		if (fi != F.end())
                                                                                        		{
                                                                                                			f.a += fi->a;
                                                                                                            			F.erase(fi);
                                                                                                                        		}
                                                                                                                                		F.insert(f);
                                                                                                                                        	}
                                                                                                                                            	double max = 0;
                                                                                                                                                	for (auto &f : F)
                                                                                                                                                    	{
                                                                                                                                                        		double rez = (double)(suma) * f.p;
                                                                                                                                                                		if (rez > max) max = rez;
                                                                                                                                                                        		suma -= f.a;
                                                                                                                                                                                	}
                                                                                                                                                                                    	cout.precision(999999999999999);
                                                                                                                                                                                        	cout << fixed << max;
                                                                                                                                                                                            }