#include <fstream>
using namespace std;
ifstream fin("stergeri.in");ofstream fout("stergeri.out");
const int nmax= 100000;
int x[nmax+1], y[nmax+1];
int main(  ) {
int n, m, k;
fin>>n>>m>>k;
for ( int i= 1; i<=m; ++i ) {
fin>>x[i]>>y[i];
}
 
for ( int i= m; i>0; --i ) {
if ( k>=x[i] ) {
k+= -x[i]+y[i]+1;
}
}
fout<<k<<"\n";
return 0;
}