#include <fstream>

using namespace std;

ifstream fin("stergeri.in");
ofstream fout("stergeri.out");

struct pereche
{
    int st,dr;

};

pereche p[100005];

int main()
{
    int n,m,i,k;
    fin>>n>>m>>k;
    for(i=1;i<=m;i++)
    {
        fin>>p[i].st>>p[i].dr;
    }
    for(i=m;i>=1;i--)
        if(p[i].st<=k)
            k+=p[i].dr-p[i].st+1;
    fout<<k;
    fin.close();
    fout.close();
    return 0;
}