#include <fstream>
#include <bitset>
using namespace std;
int n,op,nr,i,poz,x[100010],y[100010];
int main () {
    ifstream fin ("stergeri.in");
    ofstream fout ("stergeri.out");
    fin>>n>>op>>nr;
    for (i=1;i<=op;i++){
        fin>>x[i]>>y[i];
    }
    poz=nr;
    for (i=op;i>=1;i--){
        if (poz>x[i]){
            poz+=(y[i]-x[i]+1);
        }
    }
    fout<<poz;
    return 0;
}