# include <fstream>
using namespace std;
ifstream f ("stergeri.in");
ofstream g ("stergeri.out");
int a[100005],b[100005],i,n,m,k,aux;

void poz (int i,int j,int &k)
{
	int i1=0,j1=-1,x;
	x=(i+j)/2;

	aux=a[i];
	a[i]=a[x];
	a[x]=aux;
	aux=b[i];
	b[i]=b[x];
	b[x]=aux;

	while (i!=j)
	{
	if (a[i]>a[j])
	{
		aux=a[i];
		a[i]=a[j];
		a[j]=aux;
		aux=b[i];
		b[i]=b[j];
		b[j]=aux;
		aux=i1;
		i1=-j1;
		j1=-aux;
	}
	i=i+i1;
	j=j+j1;
	}
k=i;
}

void quick (int li,int ls)
{
int k;
 if (li<ls)
 {
	poz (li,ls,k);
	quick (li,k-1);
	quick (k+1,ls);
 }
}


int main ()
{
	f>>n>>m>>k;
	for (i=1;i<=m;i++)
		f>>a[i]>>b[i];
	
	quick (1,m);
	i=1;
	while (k>=a[i] && i<=m)
	{
		k+=b[i]-a[i]+1;
		i++;
	}
	g<<k;
	return 0;
}