#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
constexpr ll MOD = 1e9 + 7;
#define pb push_back
#define pli pair<ll,int>
#define pr make_pair
#define ft first
#define sd second
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n;
cin >> n;
map<ll,ll> mp;
for(int i = 0; i < n; ++i)
{
ll a, b;
cin >> a >> b;
mp[a] += b;
}
int sz = static_cast<int>(mp.size());
ll mn = mp.begin()->ft, mx = mp.begin()->ft;
ll val = 0;
vector<ll> dp(sz+1,0);
int i = 1;
for(auto it = mp.begin(); it != mp.end(); ++it, ++i)
{
mx = it->ft;
val += it->sd;
ll tmp1 = val - (mx-mn);
if(tmp1 <= it->sd)
{
dp[i] = it->sd;
val = it->sd;
mn = mx = it->ft;
continue;
}
dp[i] = tmp1;
}
sort(dp.begin()+1,dp.end());
cout << dp[sz] << '\n';
return 0;
}
