# include <fstream>
using namespace std;
ifstream fi("stergeri.in");
ofstream fo("stergeri.out");
const int nmax=100005;
int x[nmax],y[nmax];
int main(void)
{
    int n,m,k;
    fi>>n>>m>>k;
    for (int i=1;i<=m;++i) fi>>x[i]>>y[i];
    for (int i=m;i;--i) if (k>=x[i]) k+=(y[i]-x[i]+1);
    fo<<k<<"\n";
    return 0;
}