#include <bits/stdc++.h>

using namespace std;

ifstream fin("stergeri.in");
ofstream fout("stergeri.out");

int n,m,k;
struct Pereche
{
    int x,y;
};
Pereche a[100003];

void Citire()
{
    int i;
    fin>>n>>m>>k;
    for(i=1;i<=m;i++)
        fin>>a[i].x>>a[i].y;
}

void Rezolvare()
{
    int i,x,y;
    for(i=m;i>=1;i--)
    {
        x = a[i].x;
        y = a[i].y;
        if(k >= x)
            k += y-x+1;
    }
    fout<<k<<"\n";
}

int main()
{
    Citire();
    Rezolvare();

    fin.close();
    fout.close();
    return 0;
}