#include<stdio.h>

long i, j, n, m, k, a[100001], b[100001
];
FILE *fin, *fout;

int main()
{
	fin = fopen("stergeri.in", "rt");
	fout = fopen("stergeri.out", "wt");	

	fscanf(fin, "%ld%ld%ld", &n, &m, &k);

	for(i = 1; i <= m; i++)
		fscanf(fin, "%ld%ld", &a[i], &b[i]);

	for(i = n; i >= 1; i--)
		if(k >= a[i])
			k += (b[i] - a[i] + 1);
		
	fprintf(fout, "%ld\n", k);	
		
	return 0;
}