#include <cstdio>

#define file_in "stergeri.in"
#define file_out "stergeri.out"

int n,m,k,poz,x[101000],y[100100];

int main()
{
	freopen(file_in,"r",stdin);
	freopen(file_out,"w",stdout);
	
	scanf("%d %d %d", &n, &m,&k);
	for (int i=1;i<=m;++i)
		 scanf("%d %d", &x[i], &y[i]);
	
	poz=k;
	for (int i=m;i>=1;--i)
	{
		if (x[i]<=poz)
			poz+=y[i]-x[i]+1;
	}
	
	printf("%d\n", poz);
	
	return 0;
	
}