/**
 *   @FileName	a.cpp
 *   @Author	kanpurin
 *   @Created	2020.06.12 19:07:35
**/

#include "bits/stdc++.h" 
using namespace std; 
typedef long long ll;

int main() {
    int n;
    cin >> n;
    vector< pair< int, int > > a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i].first >> a[i].second;
    }
    constexpr int INF = 1e9 + 6;
    vector< vector< int > > dp(1 << n, vector< int >(n, INF));
    for (int i = 0; i < n; i++) {
        dp[(1<<i)][i] = 0;
    }
    for (int i = 3; i < 1<<n; i++) {
        for (int j = 0; j < n; j++) {
            if (i & (1 << j)) {
                for (int k = 0; k < n; k++) {
                    if ((i ^ (1 << j)) & (1 << k)) {
                        dp[i][j] = min(dp[i][j],max(dp[i ^ (1<<j)][k],a[k].second - a[k].first + a[j].first));
                    }
                }
            }
        }
    }
    int ans = INF;
    for (int i = 0; i < n; i++) {
        ans = min(ans,dp[(1<<n)-1][i]);
    }
    cout << ans << endl;
    return 0;
}