#include <stdio.h>
FILE *f=fopen("stergeri.in","r"),*g=fopen("stergeri.out","w");
long long n,m,k,i,a[100001],b[100001];
int main(void)
{
	fscanf(f,"%lld%lld%lld",&n,&m,&k);
	for (i=1;i<=m;i++)
	{
		fscanf(f,"%lld%lld",&a[i],&b[i]);
	}
	for (i=m;i>=1;i--)
	{
		if (a[i]<k)
			k=k+b[i]-a[i]+1;
	}
	fprintf(g,"%lld",k);
	fclose(g);
	return 0;
}