III

#include <iostream>
#include <vector>
#include <algorithm>

#define ll long long
#define a v[i].first
#define b v[i].second

using namespace std;

int main ()
{
    int n;
    cin >> n;

    vector< pair<ll,ll> >v (n);
    for (int i=0; i<n; i++)
        cin>>a>>b;
    sort ( v.begin (), v.end() );

    ll t = 0;
    for (int i=0; i<n; i++)
    {
        if (a > t)
            t = a;
        t += b;
    }
    cout << t << endl;

    return 0;
}