#include <fstream>
using namespace std;
ifstream fin ("stergeri.in");
ofstream fout ("stergeri.out");
int n,m,k,i,a[100001],b[100001];
int main ()
{
    fin>>n>>m>>k;
    for (i=1; i<=m; i++)
        fin>>a[i]>>b[i];
    for (i=m; i>0; i--)
    {
        if (k>=a[i])
            k+=b[i]-a[i]+1;
    }
    fout<<k;
    return 0;
}