# include <stdio.h>

FILE *f,*g;

long n,m,k,i,a[100001][3];

int main()
{

 f=fopen("stergeri.in","r");
 g=fopen("stergeri.out","w");

 fscanf(f,"%ld %ld %ld", &n, &m, &k);
 for (i=1;i<=m;i++)
	fscanf(f,"%ld %ld", &a[i][1], &a[i][2]);
 fclose(f);
 for (i=m;i>=1;i--)
	if (a[i][1]<=k)
		k+=a[i][2]-a[i][1]+1;
 fprintf(g,"%ld", k);
 fclose(g);

 return 0;
}