#include <fstream>
using namespace std;
ifstream f("stergeri.in");
ofstream g("stergeri.out");
int n,m,k,i,x[100001],y[100001];
int main()
{
    f >> n >> m >> k;
    for(i = 1; i <= m; ++i)
        f >> x[i] >> y[i];
    for(i = 1; i <= m; ++i)
        if(k >= x[m - i + 1])
            k += y[m - i + 1] - x[m - i + 1] + 1;
    g << k << '\n';
    return 0;
}