#include <iostream>
#include <fstream>

using namespace std;

int n, m, k;
struct intervale
{
    int x, y;
};
intervale st[100010];

inline void Solve()
{
    ifstream f("stergeri.in");
    f>>n>>m>>k;
    int i;
    for(i=1; i<=m; i++)
        f>>st[i].x>>st[i].y;
    f.close();

    for (i=m; i; i--)
    {
        if (st[i].x <= k)
        {
            k+=st[i].y - st[i].x + 1;
        }
    }
    ofstream g("stergeri.out");
    g<<k<<"\n";
    g.close();

}

int main()
{
    Solve();
    return 0;
}