#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int N;
vector<pair<int,int>> P;
vector<int> Q;
int GetMax()
{
	int Max=0;
	for (int i=0;i<N-1;i++){
		int x=P[Q[i]].second - P[Q[i]].first + P[Q[i+1]].first;
		if (Max<x){
			Max=x;
		}
	}
	return Max;
}
int main(int argc, char* argv[])
{

	cin>>N;
	int i;
	int Min=1000;
	for (i=0;i<N;i++){
		int A,B;
		cin>>A>>B;
		P.push_back(make_pair(A,B));
		Q.push_back(i);
	}
	do{
		int MinP=GetMax();
		if (Min>MinP){
			Min=MinP;
		}
	}while(next_permutation(Q.begin(),Q.end()));
	cout<<Min<<endl;
	return 0;
}