#include<stdio.h>
int x,i,n,m,k;
struct interv{
int a;
int b;
}v[100001];
FILE *fin,*fout;
int main(){
fin=fopen("stergeri.in","r");
fout=fopen("stergeri.out","w");
fscanf(fin,"%d %d %d",&n,&m,&k);
for(i=1;i<=m;i++){
	fscanf(fin,"%d %d",&v[i].a,&v[i].b);
}
for(i=m;i>=1;i--){
	if(v[i].a<=k){
		k+=v[i].b-v[i].a+1;
	}
}
fprintf(fout,"%d",k);
return 0;}