#include <stdio.h>
long i, j, t, x, y, n, m, k;
bool v[30000001];
int main(void)
{
freopen("stergeri.in", "r", stdin);
freopen("stergeri.out", "w", stdout);
scanf("%ld%ld%ld", &n, &m, &k);
for (i=1;i<=m;i++)
	{
   scanf ("%ld%ld", &x, &y);
   t=0;
   for (j=x;t!=y-x+1;j++)
   	if (!v[j])
      	{
   		v[j]=1;
         t++;
     	 	}
   }
t=0;
for (i=1;i<=n&&t!=k;i++)
	if (!v[i])
   	t++;
printf ("%ld", i-1);
fcloseall();
return 0;
}