#include<stdio.h>

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

int N,M,K,k,X[100005],Y[100005],i;

int main () {
	fscanf(f,"%d %d %d",&N,&M,&K);
	k = K;
	for ( i = 1 ; i <= M ; ++i )
		fscanf(f,"%d %d",&X[i],&Y[i]);
	for ( i = M ; i >= 1 ; --i ){
		if ( k >= X[i] )
			k += Y[i] - X[i] + 1;
	}
	fprintf(g,"%d",k);
	
	fclose(f);
	fclose(g);
	
	return 0;
}