#include <algorithm>
#include <iostream>
#include <fstream>
using namespace std;
ifstream in("stergeri.in");
ofstream out("stergeri.out");
const int maxn = 100005;
pair <int, int> v[maxn];
int main()
{
    int n, m, k;
    in >> n >> m >> k;
    for(int i = 1; i <= n; i++)
        in >> v[i].first >> v[i].second;
    reverse(v + 1, v + m + 1);
    int rez = k;
    for(int i = 1; i <= m; i++)
        if(rez >= v[i].first)
            rez = rez + v[i].second - v[i].first + 1;
    out << rez << "\n";
    return 0;
}