#include<cstdio>
#include<algorithm>
using namespace std;
int main()
{
	int n,m,k,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);
		if(k>=a) k+=b-a+1;
	}
	printf("%d",k);
	return 0;
}