#include <fstream>
using namespace std;
ifstream fin("stergeri.in");
ofstream fout("stergeri.out");
int n,x,k,x2,i,pos,a[100010],b[100010];
int main () {
    fin>>n>>x>>k;
    for (i=1;i<=x;i++) {
        fin>>a[i]>>b[i];
    }
    pos=k;
    for (i=x;i>=1;i--) {
        if (a[i]<=pos) {
            pos+=(b[i]-a[i]+1);
        }
    }
    fout<<pos;
}