#include<cstdio>
#include<algorithm>
using namespace std;
int main()
{
	int n,m,k,a,b,A,B;
	freopen("stergeri.in","r",stdin);
	freopen("stergeri.out","w",stdout);
	scanf("%d%d%d",&n,&m,&k);
	for(int i=1;i<=m;i++)
	{
		scanf("%d%d",&A,&B);
		a=1; b=A-1;
		if(a<k) k+=(b-a+1);//k=k+(min(k,b)-min(k,a));
		if(a==k) k+=(b-a);
		a=B+1; b=n;
		if(a<k) k+=(b-a+1);//k=k+(min(k,b)-min(k,a));
		if(a==k) k+=(b-a);
	}
	printf("%d",k);
	return 0;
}