#include<stdio.h>
long long n,m,k,a[2][100000];
void read()
{
	FILE*f=fopen("stergeri.in","r");
	fscanf(f,"%lld%lld%lld",&n,&m,&k);
	int i;
	for(i=m-1;i>=0;--i)
	fscanf(f,"%lld%lld",&a[0][i],&a[1][i]);
	fclose(f);
}
int main()
{
	read();
	int i=0;
	for(;i<m;++i)
	{
		if(a[0][i]<=k)k+=(a[1][i]-a[0][i]+1);
	}
	FILE*g=fopen("stergeri.out","w");
	fprintf(g,"%lld\n",k);
	fclose(g);
	return 0;
}