#include<stdio.h>
int v[100010],l[100010],N,M,K;
int main()
{
freopen("stergeri.in","r",stdin);
freopen("stergeri.out","w",stdout);
scanf("%d %d %d",&N,&M,&K);
    for(int i=1;i<=M;++i)
    {
    scanf("%d%d",&v[i],&l[i]);
    }
for(int i=M;i>=1;--i)
{
if(v[i]<=K)
{

K=K+(l[i]-v[i]+1);
}
}
printf("%d",K);




}