#include<iostream>
#include<fstream>
#include<vector>
using namespace std;

ifstream f("stergeri.in");
ofstream g("stergeri.out");

int n,poz;
vector<pair<int,int>> v;

void citire()
{
    f>>n>>n>>poz;
    for(int i=1;i<=n;i++)
    {
        int x,y;
        f>>x>>y;
        v.push_back({x,y});
    }
}

void solve()
{
    for(int i=v.size()-1;i>=0;i--)
    {
        if(v[i].first <= poz)
            poz = poz + (v[i].second-v[i].first+1);
    }
    g<<poz;
}

int main()
{
    citire();
    solve();
}