#include <iostream>
#include <fstream>

using namespace std;

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

const int MMAX = 100005;

struct interval
{
    long long start;
    long long stop;
};

interval a[MMAX];

int main()
{
    long long n;
    long long m,k;
    fin >> n >> m >> k;
    for(int i=1;i<=m;i++)
    {
        fin >> a[i].start >> a[i].stop;
    }
    for(int i=m;i>=1;i--)
    {
        if(a[i].start<=k) k+=(a[i].stop-a[i].start+1);
    }
    fout << k;
    return 0;
}