#include <fstream>
using namespace std;
ifstream f("Stergeri.in");
ofstream g("Stergeri.out");
int n,m,k,x[101],y[101];
int main()
{
    f >> n >> m >> k;
    for(int i=1; i<=n; i++)
        f >> x[i] >> y[i];
    for(int i=m; i>=1; i--)
    {
        if(k>=x[i]) k = k + y[i] - x[i] + 1;
    }
    g << k;
    g.close();
    return 0;
}