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