#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;
}