#include<fstream>
using namespace std;
int n,m;
struct margini{
       int st;
       int dr;};
margini v[100005];
long long k;
int main()
{
    ifstream fin("stergeri.in");
    ofstream fout("stergeri.out");
    fin>>n>>m>>k;
    int i;
    for(i=1;i<=m;i++)
       fin>>v[i].st>>v[i].dr;
    for(i=m;i>=1;i--) 
       if(v[i].st<=k)
          k=k+v[i].dr-v[i].st+1;      
    fout<<k;
    return 0;
      }