#include <fstream>

using namespace std;
ifstream f("stergeri.in");
ofstream g("stergeri.out");
int n,m,i,k,x[100005],y[100005];
int main()
{
    f>>n>>m>>k;
    for(i=1; i<=m; i++)
    {
        f>>x[i]>>y[i];
    }
    for(i=m; i>=1; i--)
    {
        if(k>=x[i])
        {
            k+=(y[i]-x[i]+1);
        }
    }
    g<<k<<"\n";
    return 0;
}