#include<fstream>
using namespace std;
ifstream fi("stergeri.in");
ofstream fo("stergeri.out");
int n,m,i,k,X[100005],Y[100005];
int main()
{
	fi>>n>>m>>k;
	for(i=1; i<=m; i++)
        fi>>X[i]>>Y[i];
    for(i=m; i>=1; i--)
    {
        if(k>=X[i])
            k+=(Y[i]-X[i]+1);
    }
	fo<<k<<"\n";
    fi.close();
    fo.close();
    return 0;
}