#include "bits/stdc++.h"
using namespace std;
#define ll long long int
#define rep(i,n) for( int i = 0; i < n; i++ )
#define rrep(i,n) for( int i = n; i >= 0; i-- )
#define REP(i,s,t) for( int i = s; i <= t; i++ )
#define RREP(i,s,t) for( int i = s; i >= t; i-- )
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define INF 2000000000
#define mod 1000000007
#define INF2 1000000000000000000

int N;
pair<int, int> A[20];
int ans = 100000;
set<int> st;

int score() {
    int ret = 0;
    rep(i, N - 1) {
        ret = max(ret, A[i].second - A[i].first + A[i + 1].first);
        //cout << A[i].second - A[i].first + A[i + 1].first << "->";
        //st.insert(A[i].second - A[i].first + A[i + 1].first);
    }
    return ret;
}

int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    cin >> N;
    rep(i, N) cin >> A[i].first >> A[i].second;
    do{
        //rep(i, N) cout << A[i].first << " " << A[i].second <<" ->";
        //cout << score() << endl;
        ans = min(score(), ans);
    }while(next_permutation(A, A + N ));
    //for(auto itr = st.begin(); itr != st.end(); ++itr) {
        //std::cout << *itr << "\n";      // イテレータの指す先のデータを表示
    //}
    cout << ans << endl;

    return 0;
}