#include <fstream>
using namespace std;
ifstream f("stergeri.in");
ofstream g("stergeri.out");
int n,m,k,i,x,y;
int main()
{
    f >> n >> m >> k;
    for(i = 1; i <= m; ++i)
    {
        f >> x >> y;
        if(x > k || y < k)
            k += y - x + 1;
    }
    g << k << '\n';
    return 0;
}