#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)

const int INF = 1e6;
int dp[1<<18][18];

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int n;
  cin >> n;
  vector<int> a(n), b(n);
  REP (i, n) cin >> a[i] >> b[i];

  REP (i, 1<<n) REP (j, n) dp[i][j] = INF;
  
  REP (i, n) dp[1<<i][i] = 0;
  REP (i, 1<<n) REP (j, n) {
    if (dp[i][j] == INF) continue;
    REP (k, n) {
      if (i & 1<<k) continue;
      dp[i|1<<k][k] = min(dp[i|1<<k][k], max(dp[i][j], b[j]-a[j]+a[k]));
    }
  }
  
  int ret = INF;
  REP (i, n) ret = min(ret, dp[(1<<n)-1][i]);
  cout << ret << endl;
  
  return 0;
}