#include <iostream>
#include <fstream>
#include <stack>

using namespace std;

struct Stergere
{
    int x, y;
    friend istream& operator>>(istream &in, Stergere &s)
    {
        return in >> s.x >> s.y;
    }
    friend ostream& operator<<(ostream &out, Stergere &s)
    {
        return out << s.x << ' ' << s.y;
    }
};

int main()
{
    ifstream fin("stergeri.in");
    int n, m, k;
    fin >> n >> m >> k;
    stack<Stergere> stergeri;
    for(int i=0; i<m; ++i)
    {
        Stergere s;
        fin >> s;
        stergeri.push(s);
    }
    while(!stergeri.empty())
    {
        Stergere stergereCurenta = stergeri.top();
        if(k > stergereCurenta.x)
            k += stergereCurenta.y - stergereCurenta.x + 1;
        stergeri.pop();
    }
    ofstream fout("stergeri.out");
    fout << k;
    return 0;
}