#include <stdio.h>
#include <ctype.h>
#define L 100003
#define MAXLOG10 10
#define BUFSIZE (128 * 1024)
using namespace std;
int x[L], y[L];
int p10[MAXLOG10+1]={0, 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000};
int rpos;
char rbuf[BUFSIZE];
static inline void initRead(){
  rpos=BUFSIZE-1;
}
static inline char readChar(){
  if(!(rpos=(rpos+1) & (BUFSIZE-1)))
    fread(rbuf, 1, BUFSIZE, stdin);
  return rbuf[rpos];
}
int getInt(){
  int ch, res=0;
  while(isspace(ch=readChar()));
  do
    res=10*res+ch-'0';
  while(isdigit(ch=readChar()));
  return res;
}
int main(){
  initRead();
  freopen("stergeri.in", "r", stdin);
  freopen("stergeri.out", "w", stdout);
  int m, k, i;
  m=getInt();
  m=getInt();
  k=getInt();
  for(i=0; i<m; i++){
    x[i]=getInt();
    y[i]=getInt();
  }
  for(i=m-1; i>=0; i--)
    if(k>=x[i])
      k=k+y[i]-x[i]+1;
  printf("%d\n", k);
  return 0;
}