#include <fstream>
using namespace std;
ifstream fin ("stergeri.in");
ofstream fout ("stergeri.out ");
int n,m,k,i,poz,a,b;
int v[200020];
int main (){

    fin>>n>>m>>poz;
    for (i=1;i<=m;i++ ) {
        fin>>a>>b;
        v[++k]=a;
        v[++k]=b;
    }
    for (i=k;i>=1;i-=2)
        if (v[i-1]<=poz)
            poz=poz+(v[i]-v[i-1])+1;


    fout <<poz<<"\n";


    return 0;
}