#include <cstdio>
using namespace std;
int n, m, a, b, k, i;
struct INTERVAL
{
    int a,b;

}x[100001];
int main(){
    freopen("stergeri.in","r",stdin);
    freopen("stergeri.out","w",stdout);
    scanf("%d%d%d",&n,&m,&k);
    for(i = 1; i <= m; i++)
        scanf("%d%d",&x[i].a,&x[i].b);

    for(i = m; i >= 1; i--){
        if(k >= x[i].a){
            k += x[i].b - x[i].a + 1;
        }
   }
    printf("%d",k);
    return 0;
}