#include <stdio.h>

struct wtf
{
	int x,y;
};


int main()
{
	int n,m,k,i;
	wtf v[100005];
	
	FILE *in  = fopen("stergeri.in","r");
	FILE *out = fopen("stergeri.out","w");
	
	fscanf(in,"%d%d%d",&n,&m,&k);
	
	for (i=0; i<m; i++)
		fscanf(in,"%d%d",&v[i].x,&v[i].y);
	
	for (i=m-1; i>=0; i--)
		if (v[i].x<k)
			k+=v[i].y-v[i].x+1;
	
	fprintf(out,"%d\n",k);

	fclose(in);
	fclose(out);
	
	return 0;
}