#include<stdio.h>
#define IN "stergeri.in"
#define OUT "stergeri.out"
#define Nmax 100001

int n,m,i,k,x,capat[2][Nmax];

void citire()
{
 scanf("%d %d %d",&n,&m,&k);
 for(i=1;i<=m;i++)
  scanf("%d %d",&capat[1][i],&capat[2][i]);
 }

void solve()
{
 for(i=m;i>=1;i--)
   {
    if(x>=capat[1][i]) x=x+capat[2][i]-capat[1][i]+1;
    }
 printf("%d\n",x);
 }



int main()
{
 freopen(IN,"r",stdin);
 freopen(OUT,"w",stdout);
 citire();
 x=k;
 solve();
  return 0;
 }