#include <fstream>
using namespace std;

ifstream cin("stergeri.in");
ofstream cout("stergeri.out");

int n, m, x, y, k, i;
struct INTERVAL
{
    int x,y;

}v[100001];

int main(){
    cin >> n >> m >> k;
    for(i = 1; i <= m; i++)
        cin >> v[i].x>> v[i].y;

    for(i = m; i >= 1; i--){
        if(k >= v[i].x){
            k += v[i].y - v[i].x + 1;
        }
   }
    cout<< k <<"\n";
    return 0;
}